Upload
dharmojayaha
View
124
Download
3
Tags:
Embed Size (px)
Citation preview
PC CONTROLLED WIRELESS ROBOT BY USING
RADIO FREQUENCY
Embedded Systems
1.1 INTRODUCTION TO EMBEDDED SYSTEMS
Each day, our lives become more dependent on 'embedded systems',
digital information technology that is embedded in our environment. More
than 98% of processors applied today are in embedded systems, and are no
longer visible to the customer as 'computers' in the ordinary sense. An
Embedded System is a special-purpose system in which the computer is
completely encapsulated by or dedicated to the device or system it controls.
Unlike a general-purpose computer, such as a personal computer, an
embedded system performs one or a few pre-defined tasks, usually with very
specific requirements. Since the system is dedicated to specific tasks, design
engineers can optimize it, reducing the size and cost of the product.
Embedded systems are often mass-produced, benefiting from economies of
scale. The increasing use of PC hardware is one of the most important
developments in high-end embedded systems in recent years. Hardware
costs of high-end systems have dropped dramatically as a result of this trend,
making feasible some projects which previously would not have been done
because of the high cost of non-PC-based embedded hardware. But software
choices for the embedded PC platform are not nearly as attractive as the
hardware.
Typically, an embedded system is housed on a single microprocessor
board with the programs stored in ROM. Virtually all appliances that have a
digital interface -- watches, microwaves, VCRs, cars -- utilize embedded
systems. Some embedded systems include an operating system, but many
are so specialized that the entire logic can be implemented as a single
program.
Physically, Embedded Systems range from portable devices such as digital
watches and MP3 players, to large stationary installations like traffic lights,
factory controllers, or the systems controlling nuclear power plants.
In terms of complexity embedded systems can range from very simple with
a single microcontroller chip, to very complex with multiple units,
peripherals and networks mounted inside a large chassis or enclosure.
Definition of an Embedded System
Embedded system is defined as, For a particular/specific application
implementing the software code to interact directly with that particular
hardware what we built. Software is used for providing features and
flexibility, Hardware = {Processors, ASICs, Memory,...} is used for
Performance (& sometimes security)
There are many definitions of embedded system but all of these can be
combined into a single concept. An embedded system is a special purpose
computer system that is used for particular task.
Features of Embedded Systems
The versatility of the embedded computer system lends itself to utility in all
kinds of enterprises, from the simplification of deliverable products to a
reduction in costs in their development and manufacture. Complex systems
with rich functionality employ special operating systems that take into
account major characteristics of embedded systems. Embedded operating
systems have minimized footprint and may follow real-time operating
system specifics.
The special computers system is usually less powerful than general-purpose
systems, although some expectations do exist where embedded systems are
very powerful and complicated. Usually a low power consumption CPU
with a limited amount of memory is used in embedded systems. Many
embedded systems use very small operating systems; most of these provide
very limited operating system capabilities.
Since the embedded system is dedicated to specific tasks, design engineers
can optimize it, reducing the size and cost of the product, or increasing the
reliability and performance. Some embedded systems are mass-produced,
benefiting from economies of scale.
Some embedded systems have to operate in extreme environment conditions
such as very high temperature & humidity.
For high volume systems such as portable music players or mobile phones,
minimizing cost is usually the primary design consideration. Engineers
typically select hardware that is just “good enough” to implement the
necessary functions.
For low volume or prototype embedded systems, general purpose computers
may be adapted by limiting the programs or by replacing the operating
system with a real-time operating system.
Characteristics of Embedded Systems
Embedded computing systems generally exhibit rich functionality—complex
functionality is usually the reason for introducing CPUs into the design.
However, they also exhibit many non-functional requirements that make the
task especially challenging:
• real-time deadlines that will cause system failure if not met;
• multi-rate operation;
• in many cases, low power consumption;
• low manufacturing cost, which often means limited code size.
Workstation programmers often concentrate on functionality. They may
consider the performance characteristics of a few computational kernels of
their software, but rarely analyze the total application. They almost never
consider power consumption and manufacturing cost. The need to juggle all
these requirements makes embedded system programming very challenging
and is the reason why embedded system designers need to understand
computer architecture.
Overview of an Embedded System Architecture
Every Embedded system consists of a custom-built hardware built around a
central processing unit. This hardware also contains memory chips onto
which the software is loaded.
Application Software
Operating System
H/W
The operating system runs above the hardware and the application software
runs above the operating system. The same architecture is applicable to any
computer including desktop computer. However these are significant
differences. It is not compulsory to have an operating system in every
embedded system. For small applications such as remote control units, air
conditioners, toys etc.
Applications of Embedded Systems
Some of the most common embedded systems used in everyday life are
Small embedded controllers: 8-bit CPUs dominate, simple or no operating system
(e.g., thermostats)Control systems: Often use DSP chip for control computations
(e.g., automotive engine control)Distributed embedded control: Mixture of large and small nodes on a real-time Embedded networks (e.g., cars, elevators, factory automation)System on chip: ASIC design tailored to application area
(e.g., consumer electronics, set-top boxes)Network equipment: Emphasis on data movement/packet flow
(e.g., network switches; telephone switches)Critical systems: Safety and mission critical computing
(e.g., pacemakers, automatic trains)Signal processing: Often use DSP chips for vision, audio, or other signal Processing (e.g., face recognition)Robotics: Uses various types of embedded computing (especially Vision and control) (e.g., autonomous vehicles)Computer peripherals: Disk drives, keyboards, laser printers, etc.Wireless systems: Wireless network-connected “sensor networks” and
“Motes” to gather and report informationEmbedded PCs: Palmtop and small form factor PCs embedded into EquipmentCommand and control: Often huge military systems and “systems of systems” (e.g., a fleet of warships with interconnected Computers)
Home Appliances, intercom, telephones, security systems, garage door
openers, answering machines, fax machines, home computers, TVs, cable
TV tuner, VCR, camcorder, remote controls, video games, cellular phones,
musical instruments, sewing machines, lighting control, paging, camera,
pinball machines, toys, exercise equipment
Office Telephones, computers, security systems, fax machines, microwave,
copier, laser printer, color printer, paging
Auto Trip computer, engine control, air bag, ABS, instrumentation, security
system, transmission control, entertainment, climate control, cellular phone,
keyless entry
TYPES OF EMBEDDED SYSTEMSBased on functionality and performance embedded systems categorized as 4 types
1. Stand alone embedded systems
2. Real time embedded systems
3. Networked information appliances
4. Mobile devices
1. Stand alone embedded systems:-
As the name implies, stand alone systems work in stand alone mode. They
take i/p, process them and produce the desire o/p. The i/p can be an
electrical signal from transducer or temperature signal or commands from
human being. The o/p can be electrical signal to drive another system an led
or lcd display
ex digital camera, microwave oven, CD player, Air conditioner etc
2. Real time embedded systems:-
In this type of an embedded system a specific work has to be complete in a particular period of time.
Hard Real time systems:- embedded real time used in missiles
Soft Real time systems:- DVD players
3. Networked information appliances:- Embedded systems that are provided with n/w interfaces and accessed by
n/w's such as local area n/w or internet are called Network Information
Appliances
Ex A web camera is connected to the internet. Camera can send pictures in
real time to any computers connected to the internet
4. Mobile devices:- Actually it is a combination of both VLSI and Embedded System
Mobile devices such as Mobile phone, Personal digital assistants, smart
phones etc are special category of embedded systems
2.2 INTRODUCTION TO MICROCONTROLLER
Based on the Processor side Embedded Systems is mainly divided into 3 types
1. Micro Processor : - are for general purpose eg: our personal computer
2. Micro Controller:- are for specific applications, because of cheaper cost we will go for these
3. DSP ( Digital Signal Processor ):- are for high and sensitive application purpose
MICROCONTROLLER VERSUS MICROPROCESSOR
A system designer using a general-purpose microprocessor such as the
Pentium or the 68040 must add RAM, ROM, I/O ports, and timers
externally to make them functional. Although the addition of external RAM,
ROM, and I/O ports makes these systems bulkier and much more expensive,
they have the advantage of versatility such that the designer can decide on
the amount of RAM, ROM and I/O ports needed to fit the task at hand.
A Microcontroller has a CPU (a microprocessor) in addition to a fixed
amount of RAM, ROM, I/O ports, and a timer all on a single chip. In other
words, the processor, the RAM, ROM, I/O ports and the timer are all
embedded together on one chip; therefore, the designer cannot add any
external memory, I/O ports, or timer to it. The fixed amount of on-chip
ROM, RAM, and number of I/O ports in Microcontrollers makes them ideal
for many applications in which cost and space are critical.
CPU platform:
Embedded processors can be broken into two distinct categories:
microprocessors (μP) and microcontrollers (μC). Microcontrollers have
built-in peripherals on the chip, reducing size of the system.
There are many different CPU architectures used in embedded designs such
as ARM, MIPS, Coldfire/68k, PowerPC, x86, PIC, 8051, Atmel AVR,
Renesas H8, SH, V850, FR-V, M32R, Z80, Z8, etc. This in contrast to the
desktop computer market, which is currently limited to just a few competing
architectures.
PC/104 and PC/104+ are a typical base for small, low-volume embedded
and ruggedized system design. These often use DOS, Linux, NetBSD, or an
embedded real-time operating system such as QNX or VxWorks.
A common configuration for very-high-volume embedded systems is the
system on a chip (SoC), an application-specific integrated circuit (ASIC), for
which the CPU core was purchased and added as part of the chip design. A
related scheme is to use a field-programmable gate array (FPGA), and
program it with all the logic, including the CPU.
Embedded systems are based on the concept of the microcontroller, a single
integrated circuit that contains all the technology required to run an
application. Microcontrollers make integrated systems possible by
combining several features together into what is effectively a complete
computer on a chip, including:
* Central Processing Unit
* Input/Output interfaces (such as serial ports)
* Peripherals (such as timers)
* ROM, EEPROM or Flash memory for program storage
* RAM for data storage
* Clock generator
By integrating all of these features into a single chip it is possible to greatly
reduce the number of chips and wiring necessary to control an electronic
device, dramatically reducing its complexity, size and cost.
* Size & Weight: Microcontrollers are designed to deliver maximum
performance for minimum size and weight. A centralized on-board computer
system would greatly outweigh a collection of microcontrollers.
* Efficiency: Microcontrollers are designed to perform repeated functions
for long periods of time without failing or requiring service.
MICRO CONTROLLER: is a chip through which we can connect many
other devices and also those are controlled by the program the program
which burn into that chip
INTRODUCTION TO 8051
Intel Corporation introduced an 8 bit micro controller called the 8051 in
1981. While the time of introduction, Intel was given some specific features
and particular name as MCS-51
Features:-
ROM ---- 4 K bytes of Memory
RAM ----- 128 bytes
Timers------2
4 ports --- 32 I/O ports ( each 8 bit wide )
Interrupts-----6
serial port-----1
all on a single chip
Many semiconductor manufacturers started either manufacturing the 8051
devices as such (Intel was liberal in giving away license to whoever asked)
or developing a new kind of microcontrollers based on 8051 core
architecture. Manufacturers modified the basic 8051 architecture and added
many new peripheral functions to make them attractive to the designers.
After that so many industries are come into picture to introduce 8051 again
wit some extra features. This has led to many versions of the 8051 with
different speeds and amounts of on-chip ROM marketed by more
manufactures those are
Dallas ------ DS4700
Zilog---------Z
Motrolla
Freescale
Atmel ------- AT89C51/52, AT89S51/52
Phillips ----- P89C51RD2Fn
Before these industries came into picture 8051 chips are made with CMOs
technology. ATmel was introduced with ISP (In System Programming)
In System Programming (ISP):-
In-System Programming (ISP) is the ability of some programmable logic
devices, microcontrollers, and other programmable electronic chips to be
programmed while installed in a complete system, rather than requiring the
chip to be programmed prior to installing it into the system. (or) In-system
programming is a valuable feature that allows system firmware to be
upgraded without disassembling the embedded system to physically replace
memory. Most Maxim 8051-based microcontrollers can be reprogrammed
from a PC or laptop via an inexpensive RS-232 serial interface and a few
logic gates
The primary advantage of this feature is that it allows manufacturers of
electronic devices to integrate programming and testing into a single
production phase, rather than requiring a separate programming stage prior
to assembling the system. This may allow manufacturers to program the
chips in their own system's production line instead of buying
preprogrammed chips from a manufacturer or distributor, making it feasible
to apply code or design changes in the middle of a production run.
2.3 AT89S52 MICROCONTROLLER
The AT89S52 is a low-power, high-performance CMOS 8-bit
microcontroller with 8K bytes of in-system programmable Flash memory.
The device is manufactured using Atmel’s high-density nonvolatile memory
technology and is compatible with the industry-standard 80C51
instruction set and pin out. The on-chip Flash allows the program memory to
be reprogrammed in-system or by a conventional nonvolatile memory
programmer. By combining a versatile 8-bit CPU with in-system
programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful
microcontroller which provides a highly-flexible and cost-effective solution
to many embedded control applications.
8051 PIN DIAGRAM
AT89S52 Architecture consists of these specific features:
8 bit CPU with registers A (Accumulator) and B
16 bit Program Counter(PC) and Data Pointer (DPTR)
8 bit Program Status Word (PSW)
8 bit Stack Pointer (SP)
Internal ROM of 8k
Internal RAM of 128 bytes
Four Register banks each containing eight registers
Sixteen bytes, which may be addressed at the bit level
Eighty bytes of general purpose data memory
32 I/O pins arranged as four 8-bit ports: P0,P1,P2,P3
Two 16-bit Timers/Counters: T0 and T1
Full duplex serial data Receiver/Transmitter : SBUF
Control Registers: TCON, TMOD, SCON, SMOD, PCON, IP and IE.
Two external and three internal interrupt sources.
Oscillator and Clock circuits.
Pin Description
Pin ( 32 – 39 ) Port 0: Port 0 is an 8-bit open drain bidirectional port. As
an open drain output port, it can sink eight LS TTL loads. Port 0 pins that
have 1s written to them float, and in that state will function as high
impedance inputs. Port 0 is also the multiplexed low-order address and data
bus during accesses to external memory. In this application it uses strong
internal pull ups when emitting 1s. Port 0 emits code bytes during program
verification. In this application, external pull ups are required.
Pin ( 1- 8 ) Port 1: Port 1 is an 8-bit bidirectional I/O port with internal pull
ups. Port 1 pins that have 1s written to them are pulled high by the internal
pull ups, and in that state can be used as inputs. As inputs, port 1 pins that
are externally being pulled low will source current because of the internal
pull ups.
Alternate Functions of Port 1 used for In system Programmable
P.5 MOSI --------- Instruction Input
P.6 MISO ---------- Data Output
P.7 SCK ----------- Clk in
Pin ( 21 – 28 ) Port 2: Port 2 is an 8-bit bidirectional I/O port with internal
pull ups. Port 2 emits the high-order address byte during accesses to external
memory that use 16-bit addresses. In this application, it uses the strong
internal pull ups when emitting 1s.
Pin (10 – 17) Port 3: Port 3 is an 8-bit bidirectional I/O port with internal
pull ups. It also serves the functions of various special features of the 80C51
Family as follows:
Port Pin Alternate Function
P3.0- RxD (serial input port)
P3.1 -TxD (serial output port)
P3.2 -INT0 (external interrupt 0)
P3.3- INT1 (external interrupt 1)
P3.4 -T0 (timer 0 external input)
P3.5 -T1 (timer 1 external input)
P3.6 -WR (external data memory write strobe)
P3.7 -RD (external data memory read strobe)
Pin 40 VCC: -Supply voltage
Pin 20 VSS: -Circuit ground potential
Pin 29 PSEN: Program Store Enable is the read strobe to external Program
Memory. When the device is executing out of external Program Memory,
PSEN is activated twice each machine cycle (except that two PSEN
activations are skipped during accesses to external Data Memory). PSEN is
not activated when the device is executing out of internal Program Memory.
Pin 30 ALE/PROG: Address Latch Enable output pulse for latching the
low byte of the address during accesses to external memory. ALE is emitted
at a constant rate of 1/6 of the oscillator frequency, for external timing or
clocking purposes, even when there are no accesses to external memory.
(However, one ALE pulse is skipped during each access to external Data
Memory.) This pin is also the program pulse input (PROG) during EPROM
programming.
Pin 31 EA/VPP: When EA is held high the CPU executes out of internal
Program Memory. Holding EA low forces the CPU to execute out of
external memory regardless of the Program Counter value. In the 80C31, EA
must be externally wired low. In the EPROM devices, this pin also receives
the programming supply voltage (VPP) during EPROM programming.
Pin 18 XTAL1: Input to the inverting oscillator amplifier.
Pin 19 XTAL2: Output from the inverting oscillator amplifier.
REGISTERS
8051 is a collection of 8 and 16 bit registers and 8 bit memory locations.
These registers and memory locations can be made to operate using the
software instructions. The program instructions control the registers and
digital data paths that are contained inside the 8051, as well as memory
locations that are located outside the 8051.
Register are used to store information temporarily, while the information
could be a byte of data to be processed, or an address pointing to the data to
be fetched. The vast majority of 8051 register are 8-bit registers.
Generally there are two types of registers. They are General purpose
Registers (GPR’s) and Special Function Registers (SFR’s)
TIMER/COUNTERS
The Atmel 80C51 Microcontrollers implement two general purpose, 16-bit
timers/ counters. They can be used either as timers to generate a time delay
or as a counter to count events happening outside the microcontroller. The
microcontroller has two 16-bit wide timers. They are identified as Timer 0
and Timer 1, and can be independently configured to operate in a variety of
modes as a timer or as an event counter. When operating as a timer, the
timer/counter runs for a programmed length of time, then issues an interrupt
request. When operating as a counter, the timer/counter counts negative
transitions on an external pin. After a preset number of counts, the counter
issues an interrupt request. Register pairs (TH0, TL0), (TH1, TL1), and
(TH2, TL2) are the 16-bit counting registers for Timer/Counters 0, 1, and 2,
respectively.
Timer 0 Register
The 16-bit register of Timer 0 is accessed as low byte and high byte. The
low byte register is called TL0 (Timer 0 low byte) and high byte register is
referred to as TH0 (Timer 0 high byte). These registers can be accessed like
any other register, such as A,B,R0,R1,R2,etc.
Timer 1 Register
Timer 1 is also 16-bits, and its 16-bit register is split into two bytes, referred
to as TL1 ( Timer 1 low byte ) and TH1 ( Timer 1 high byte ). These
registers are accessible in the same way as the registers of timer 0.
TMOD Register (timer mode)
TMOD: Timer/Counter Mode Control Register.
Not Bit Addressable.
Timer 1 Timer 0
GATE When TRx (in TCON) is set and GATE=1, Timer/CounterX will run
only while INTx pin is high (hardware control). When GATE=0,
Timer/Counter will run only while TRx=1 (software
control).
C/T Timer or Counter selector. Cleared for Timer operation (input from
internal system clock). Set for Counter operation (input from TX
input pin).
M1 Mode selector bit.
M0 Mode selector bit.
M1 M0 Mode Operating Mode
0 0 0 13-bit Timer (8048 compatible) (TH1)
0 1 1 16-bit Timer/Counter
1 0 2 8-bit Auto-Reload Timer/Counter (TL1). Reloaded from TH1 at overflow.
1 1 3 timer 1 halted. Retains count.
1 1 3 (Timer 1) Timer/Counter 1 stopped.
TCON: Timer/Counter Control Register
Bit Addressable.
TF1 Timer1 overflow flag. Set by hardware when the Timer/Counter 1
overflows. Cleared by hardware as processor vectors to the interrupt
service routine.
TR1 Timer 1 run control bit. Set/cleared by software to turn Timer/Counter 1
ON/OFF.
The lower 4 bitsare set aside forcontrolling theinterrupt bits
The upper four bits are used tostore the TF andTR bits of bothtimer 0 and 1
TF0 Timer0 overflow flag. Set by hardware when the Timer/Counter 0
overflows. Cleared by hardware as processor vectors to the service
routine.
TR0 Timer 0 run control bit. Set/cleared by software to turn Timer/Counter 0
ON/OFF.
IE1 External Interrupt 1 edge flag. Set by hardware when External terrupt
edge is detected. Cleared by hardware when interrupt is processed.
IT1 Interrupt 1 type control bit. Set/cleared by software to specify falling edge/low
level triggered External Interrupt.
IE0 External Interrupt 0 edge flag. Set by hardware when External Interrupt
edge is detected. Cleared by hardware when interrupt is processed.
IT0 Interrupt 0-type control bit. Set/cleared by software to specify falling
edge/low level triggered External Interrupt.
2.5 SERIAL COMMUNICATION
The 8051 serial port is full duplex. In other words, it can transmit and
receive data at the same time. Unlike any other register in the 8051, SBUF is in
fact two distinct registers - the write-only register and the read-only register.
Transmitted data is sent out from the write-only register while received data is
stored in the read-only register. There are two separate data lines, one for
transmission (TXD) and one for reception (RXD). Therefore, the serial port can
be transmitting data down the TXD line while it is at the same time receiving
data on the RXD line. The TXD line is pin 11 of the microcontroller (P3.1)
while the RXD line is on pin 10 (P3.0)
Serial data communication uses two methods, asynchronous and synchronous.
The synchronous method transfers a block of data (characters) at a time, while
the asynchronous method transfers a single byte at a time. It is possible to write
software to use either of these methods, but the programs can be tedious and
long. For this reason, there are special IC chips made by many manufacturers
for serial data communications. These chips can be commonly referred to as
UART (Universal Asynchronous Receiver-transmitter) and USART ( Universal
Synchronous Asynchronous Receiver-Transmitter). The 8051 chip has a built-in
UART.
Asynchronous Serial Communication and Data Framing
Start Bits and Stop Bits
In the asynchronous method is character is placed between start and stop bits,
this is called data framing. In asynchronous communication, at least two extra
bits are transmitted with the data word; a start bit and a stop bit. Therefore, if
the transmitter is using an 8-bit system, the actual number of bits transmitted
per word is ten. In most protocols the start bit is a logic 0 while the stop bit is
logic 1. Therefore, when no data is being sent the data line is continuously
HIGH. The receiver waits for a 1 to 0 transition. In other words, it awaits a
transition from the stop bit (no data) to the start bit (logic 0). Once this
transition occurs the receiver knows a data byte will follow. Since it knows the
data rate (because it is defined in the protocol) it uses the same clock as
frequency as that used by the transmitter and reads the correct number of bits
and stores them in a register. For example, if the protocol determines the word
size as eight bits, once the receiver sees a start bit it reads the next eight bits and
places them in a buffer. Once the data word has been read the receiver checks to
see if the next bit is a stop bit,signifying the end of the data. If the next bit is not
a logic 1 then something went wrong with the transmission and the receiver
dumps the data. If the stop bit was received the receiver waits for the next data
word, ie; it waits for a 1 to 0 transition.
Baud Rates in the 8051
XTAL = 11.0592 MHz:
The frequency of system clock = 11.0592 MHz / 12 = 921.6 kHz
The frequency sent to timer 1 = 921.6 kHz/ 32 = 28,800 Hz
(a) 28,800 / 3 = 9600 where -3 = FD (hex) is loaded into TH1
(b) 28,800 / 12 = 2400 where -12 = F4 (hex) is loaded into TH1
(c) 28,800 / 24 = 1200 where -24 = E8 (hex) is loaded into TH1
SBUF
Goes out first
XTAL oscillator
÷ 12÷ 32
By UART
Machine cycle frequency
28800 Hz
To timer 1 To set the Baud rate
921.6 kHz
11.0592 MHz
Timer 1
SBUF is an 8-bit register used solely for serial communication in the 8051.
For a byte of data to be transferred via the TxD line, it must be placed in the
SBUF register. Similarly, SBUF holds the byte of data when it is received
by the 8051’s RxD line. SBUF can be accessed like any other register in the
8051.
The moment a byte is written into SBUF, it is framed with the start and stop
bits and transferred serially via the TxD pin. Similarly, when the bits are
received serially via RxD, the 8051 deframes it by eliminating the stop and
start bits, making a byte out of the data received, and then placing it in the
SBUF.
DATA TRANSMISSION: -
Transmission of serial data bits begins anytime data is written to sbuf.
" TI " (SCON) set to 1 when data has been transmitted and signifies that "
SBUF " is empty and that another data byte can be sent.
DATA RECEPTION: -
Reception of serial data will begin if the receive enable bit (REN) in
SCON is set to ' 1 ' for all modes. For mode ' 0 ' only RI must be cleared to
0. Receiver interrupt flag ' RI ' (in SCON) is set after data has been received
in all modes. Setting of ' REN ' bit is a direct program control that limits the
reception of unexpected data.
SCON ( Serial Control ) Register
SM0 SM1 SM2 REN TB8 RB8 TI RI
Mode 0: Serial data enters and exits through RxD. TxD outputs the shift clock. 8 bits are transmitted/received (LSB first). The baud rate is fixed at 1/12 the oscillator frequency.
Mode 1: 10 bits are transmitted (through TxD) or received (through RxD): a
start bit (0), 8 data bits (LSB first), and a stop bit (1). On receive, the stop bit
goes into RB8 in Special Function Register SCON. The baud rate is
variable.
Mode 2: 11 bits are transmitted (through TxD) or received (through RxD):
start bit (0), 8 data bits (LSB first), a programmable 9th data bit, and a stop
bit (1). On Transmit, the 9th data bit (TB8 in SCON) can be assigned the
value of 0 or 1. Or, for example, the parity bit (P, in the PSW) could be
moved into TB8. On receive, the 9th data bit goes into RB8 in Special
Function Register SCON, while the stop bit is ignored. The baud rate is
programmable to either 1/32 or 1/64 the oscillator frequency.
Mode 3: 11 bits are transmitted (through TxD) or received (through RxD): a
start bit (0), 8 data bits (LSB first), a programmable 9th data bit, and a stop
bit (1). In fact, Mode 3 is the same as Mode 2 in all respects except baud
rate. The baud rate in Mode 3 is variable. In all four modes, transmission is
initiated by any instruction that uses SBUF as a destination register.
Reception is initiated in Mode 0 by the condition RI = 0 and REN = 1.
Reception is initiated in the other modes by the incoming start bit if REN =
1.
SM2 Enables the multiprocessor communication feature in Modes 2 and 3.
In Mode 2 or 3, if SM2 is set to 1, then Rl will not be activated if the
received 9th data bit (RB8) is 0. In Mode 1, if SM2=1 then RI will not be
activated if a valid stop bit was not received. In Mode 0, SM2 should be 0.
REN Enables serial reception. Set by software to enable reception. Clear by
software to disable reception.
TB8 The 9th data bit that will be transmitted in Modes 2 and 3. Set or clear
by software as desired.
RB8 In Modes 2 and 3, is the 9th data bit that was received. In Mode 1, it
SM2=0, RB8 is the stop bit that was received. In Mode 0, RB8 is not used.
TI (Transmit Interrupt)
This is an extremely important flag bit in the SCON register. When the 8051
finishes the transfer of the 8-bit character it raises the TI flag to indicate that
it is ready to transfer another byte. The TI bit is raised at the beginning of the
stop bit.
RI ( Receive Interrupt)
This is an extremely important flag bit in the SCON register. When the 8051
receives data serially via RxD, it gets rid of the start and stop bits and places
the byte in the SBUF register. Then it raises the RI flag bit to indicate that a
byte has been received and chould be picked up before it is lost.
INTERRUPTS
An interrupt is a special feature which allows the 8051 to provide the
illusion of "multi-tasking," although in reality the 8051 is only doing one
thing at a time. The word "interrupt" can often be substituted with the word
"event."
An interrupt is triggered whenever a corresponding event occurs. When the
event occurs, the 8051 temporarily puts "on hold" the normal execution of
the program and executes a special section of code referred to as an interrupt
handler. The interrupt handler performs whatever special functions are
required to handle the event and then returns control to the 8051 at which
point program execution continues as if it had never been interrupted.
Interrupt Service Routine
For every interrupt, there must be an interrupt service routine (ISR). Or
interrupt handler. When an interrupt is invoked, the microcontroller runs the
interrupt service routine. For every interrupt, there is a fixed location in
memory that holds the address of its ISR. The group of memory locations set
aside to hold the addresses of the ISRs is called interrupt vector table.
Six Interrupts in 8051
1. Reset : When the reset pin is activated, the 8051 jumps to address location 0000
2. Two interrupts are set aside for the timers: one for the Timer 0 and one for Timer1.
3. Two interrupts are set aside for hardware external interrupts : one for INT0 and one for INT1
4. Serial communication has a single interrupt that belongs to both receive and transmit.
Enabling Interrupt (IE) Register
All interrupt are disabled after reset
We can enable and disable them bye IE
EA -- ET2 ES ET1 EX1 ET0 EX0
EA IE.7 If EA=0, disables all interrupts, no interrupt is acknowledged
If EA=1, each interrupt source is individually enabled or disabled by setting or clearing its enable bit.
-- IE.6 Not implemented, reserved for future use.
ET2 IE.5 Enables or disables Timer2 overflow or capture interrupt
(8052 only)
ES IE.4 Enables or disables the serial port interrupt.
ET1 IE.3 Enables or disables Timer 1 overflow interrupt.
EX1 IE.2 Enables or disables external interrupt 1.
ET0 IE.1 Enables or disables Timer 0 overflow interrupt.
EX0 IE.0 Enables or disables external interrupt 0.
Interrupt Priority (IP) Register
0= lower priority, 1= higher priority, reset IP=00H
Lower priority ISR can be interrupted by a high priority interrupt.
A high priority ISR can not be interrupted.
Low-priority interrupt wait until 8051 has finished servicing the high-priority interrupt.
-- -- PT2 PS PT1 PX1 PT0 PX0
-- IP.7 Reserved
-- IP.6 Reserved
PT2 IP.5 Timer2 interrupt priority bit (8052 only)
PS IP.4 serial port interrupt priority bit.
PT1 IP.3 Timer 1 interrupt priority bit.
PX1 IP.2 external interrupt 1 priority bit.
PT0 IP.1 Timer 0 interrupt priority bit.
PX0 IP.0 external interrupt 0 priority bit.
BASIC REQUIRMENT
The following are the basic five requirements of microcontroller
1. Power Supply
2. Crystal Oscillator
3. Reset
4. SIP Resistor
5. Resistor for EA Pin
1. Regulated Power Supply
In mains-supplied electronic systems the AC input voltage must be
converted into a DC voltage with the right value and degree of stabilization.
The common DC voltages that are required to power up the devices are
generally in the range of 3 VDC to 30 VDC. Typically the fixed types of DC
voltages are 5V, 9V, 12V, 15V and 18V DC.
POWER SUPPLY MODULES:
STEP DOWN TRANSFORMER
BRIDGE RECTIFIER WITH FILTER
VOLTAGE REGULATORS
Transformer
Transformers convert AC electricity from one voltage to another with little
loss of power. Transformers work only with AC and this is one of the
reasons why mains electricity is AC. Step-up transformers increase voltage,
step-down transformers reduce voltage.
A step down power transformer is used to step down the AC voltage from
the line voltage
of 110 VAC or 220 VAC i.e, it converts higher voltage at the input side to a lower voltage at the output.
Rectifier
There are several ways of connecting diodes to make a rectifier to convert
AC to DC. The bridge rectifier is the most important and it produces full-
wave varying DC
Bridge rectifier Output: full-wave varying DC
Alternate pairs of diodes conduct, changing over (using all the AC wave)
the connections so the alternating directions of
AC are converted to the one direction of DC.
Filter
Filtering is performed by a large value electrolytic capacitor connected
across the DC supply to act as a reservoir, supplying current to the output
when the varying DC voltage from the rectifier is falling. The diagram
shows the unfiltered varying DC (dotted line) and the filtered DC (solid
line). The
capacitor charges quickly near the peak of the varying DC, and then
discharges as it supplies current to the output.
Typically 1000 μf capacitor is used
Regulator
This is a simple DC regulated supply project using 7805 voltage regulator to
obtain a variable DC voltage range from 5V to 15V
Pin out of the 7805 regulator IC.
1. Unregulated voltage in
2. Ground
3. Regulated voltage out
If you need other voltages than +5V, you can modify the circuit by replacing
the 7805 chips with another regulator with different output voltage from
regulator 78xx chip family. The last numbers in the the chip code tells the
output voltage. Remember that the input voltage must be at least 3V greater
than regulator output voltage ot otherwise the regulator does not work well.
Crystal Oscillator
The 8051 uses the crystal for precisely that: to synchronize it’s operation.
Effectively, the 8051 operates using what are called "machine cycles." A
single machine cycle is the minimum amount of time in which a single 8051
instruction can be executed. Although many instructions take multiple
cycles. 8051 has an on-chip oscillator. It needs an external crystal that
decides the operating frequency of the 8051. The crystal is connected to pins
18 and 19 with stabilizing capacitors. 12 MHz (11.059MHz) crystal is often
used and the capacitance ranges from 20pF to 40pF.
A cycle is, in reality, 12 pulses of the crystal. That is to say, if an instruction
takes one machine cycle to execute, it will take 12 pulses of the crystal to
execute. Since we know the we can calculate how many instruction cycles
the 8051 can execute per second:
11,059,000 / 12 = 921,583
11.0592 MHz crystals are often used because it can be divided to give you
exact clock rates for most of the common baud rates for the UART,
especially for the higher speeds (9600, 19200).
Reset RESET is an active High input When RESET is set to High, 8051 goes back
to the power on state.The 8051 is reset by holding the RST high for at least
two machine cycles and then returning it low. Initially charging of capacitor
makes RST High, When capacitor charges fully it blocks DC.
SIP Resistor
Sip Resistor is a single in pack Resistor (i.e.,) 8 resistors connected in series.
Basically SIP resistor is a 9 pin connector first pin is for power supply to the
entire 8 resistors in SIP.
Generally SIP Resistor is used to close the open drain connections of Port 0.
CHAPTER 4
BLOCK DIAGRAM
ENCODER
MAX 232
RF TX
PC
MICROCONTROLLER
AT89S52
RPS
Crystal
BLOCK DIAGRAM EXPLANATION:
A robot can talk, walk, run and do anything as per logic embedded in it even though the
robot can do the above things. It seems a useless thing if it is uncontrollable. Here
controlling a robot is main task has to consider while designing any robot.
DECODER
L293D
RF RX
MICROCONTROLLER
AT89S52
RPS
Crystal
ROBOTPLATFORM
In this project a robot is controlled by using our personal computer. Rf transmitter
will be attached to the pc and the rf receiver will be connected with the receiver means
robot.
in this project there are two embedded systems based microcontroller boards.
Among which one is transmitter connected to the pc through max 232 and the receiver
board has a robot platform. When ever we want control the robot the commands are given
from the pc keyboard and these commands are encoded and transmitted through rf tx and
the code is received by rf rx and decoded in the decoder. Depending upon the command
received the control compare with the predefined commands programmed. Depending
upon the command received the robot will be controlled.
The receiver consists of dc motors interfaced to microcontroller through h-bridge
driver. The role of the h-bridge is to provide the commutation action. Two bits are
required for controlling the motor. Braking also may be programmed in to the micro
controller.
Chapter 5
HARDWARE IMPLEMENTATION
RF Trnsmitter RF 1 433/315 MHz (SP)Radio frequency (RF) transmitters are widely used in radio frequency communications systems. With the increasing availability of efficient, low cost electronic modules, mobile communication systems are becoming more and more widespread. Wireless communications systems, including cellular phones, paging devices, personal communication services (PCS) systems, and wireless data networks, have become ubiquitous in society. Generally, a radio transmitter and receiver is used for performing a radio transmission and receiving operation, whereby a high frequency signal outputted from a modulator is transmitted to an antenna of the radio transmitter and is transmitted therefrom to a remote radio transmitter and receiver, or the thusly transmitted signal is received through another antenna. The transmitting baseband signal is subjected to a predetermined signal process, input to a modulator, which modulates a carrier wave signal. The modulated carrier wave signal is converted into a radio frequency by a transmitting radio-frequency circuit and amplified to a predetermined transmitting power. In general, the function of a radio frequency (RF) transmitter is to modulate, upconvert, and amplify signals for transmission into free space. An RF transmitter generally includes a modulator that modulates an input signal and a radio frequency power amplifier that is coupled to the modulator to amplify the modulated input signal. The radio frequency power amplifier is coupled to an antenna that transmits the amplified modulated input signal.SpecificationsVoltage : 3 to 12 voltsCurrent : 10 to 15 mAWorking Mode : AMSpeed : 4 KbpsFrequency : 315/433 MHzExtrenal Antenna : 315 MHzPin Out
1. Data
2. Vdd
3. Vss
4. Antena
Encoder HT 640
General Description
Encoders are a series of CMOS LSIs for remote control system applications. They are capable of encoding 18 bits of information which consists of N address bits and 18_N data bits. Encoders offer flexible combinations of programmable address/data to meet various application needs. The programmable address/ data is transmitted together with the header bits via an RF or an infrared transmission medium upon receipt of a trigger signal.
Pin Assignment
Features_ Operating voltage: 2.4V~12V_ Low power and high noise immunity CMOS technology_ Low standby current_ Three words transmission_ Built-in oscillator needs only 5% resistor
_ Easy interface with an RF or infrared transmission media_ Minimal external componentsApplications_ Burglar alarm system_ Smoke and fire alarm system_ Garage door controllers_ Car door controllers_ Car alarm system_ Security system_ Cordless telephones
_ Other remote control systems
RF Receiver Module
RF 1 433/315 MHz(SP)
Specification
Voltage : 5v
Frequcncy : 315/433 MHz
External Antena : 315 MHz
Speed : 4KB/S
Current : 0.5-0.8 mA
PIN OUT
1. Vdd 2. Data Out
3. Vss
Decoders HT 648
General Description
The decoders are a series of CMOS LSIs for remote control system applications.
They are paired with the series of encoders. For proper operation a pair of
encoder/decoder pair with the same number of address and data format should be
selected (refer to the encoder/
decoder cross reference tables). The series of decoders receives serial address and
data from that series of encoders that are transmitted by a carrier using an RF or an
IR transmission medium. It then compares the serial input data twice continuously
with its local address. If no errors or unmatched codes are encountered, the input
data codes are decoded and then transferred to the output pins. The VT pin also
goes high to indicate a valid transmission. The decoders are capable of decoding
18 bits of information that consists of N bits of address and 18–N bits of data. To
meet various applications they are arranged to provide a number of data pins
whose range is from 0 to 8 and an address pin whose range is from 8 to 18.
Pin Assignment
Features
· Operating voltage: 2.4V~12V· Low power and high noise immunity CMOStechnology· Low standby current· Capable of decoding 18 bits of information· Pairs with HOLTEK’s 318 series of encoders· 8~18 address pins· 0~8 data pins· Trinary address setting· Two times of receiving check· Built-in oscillator needs only a 5% resistor· Valid transmission indictor· Easily interface with an RF or an infraredtransmission medium
· Minimal external components
Applications
· Burglar alarm system· Smoke and fire alarm system· Garage door controllers· Car door controllers· Car alarm system· Security system· Cordless telephones
· Other remote control systems
H-Bridge driver L293D
As the MCUs PORT are not powerful enough to drive DC motors
directly so we need some kind of drivers. A very easy and safe is to use
popular L293D chips. It is a 16 PIN chip. The pin configuration is as follows.
L293D Dual DC Motor ControllerThis chip is designed to control 2 DC motors. There are 2 INPUT and 2 OUTPUT PINs for each motors. The connection is as follows.
Motor Controller Using L293d chipThe behavior of motor for various input conditions are as follows
A B
Stop Low LowClockwise Low High
Anti Clockwise High Low
Stop High High
So you saw you just need to set appropriate levels at two PINs of the
microcontroller
to control the motor. Since this chip controls two DC motors there are two more
output pins (output3 and output4) and two more input pins(input3 and input4).
The INPUT3 and INPUT4 controls second motor in the same way as listed
above for
input A and B. There are also two ENABLE pins they must be high(+5v) for
operation, if they are pulled low(GND) motors will stop.The following program
starts
the motor runs it one direction for some time and then reverses the direction.
Speed Control
The speed of DC motor can also be controlled with MCU. PWM or pulse
width
Modulation technique is used to digitally control speed of DC motors.
Working Theory of H-Bridge
The name "H-Bridge" is derived from the actual shape of the switching
circuit which control the motoion of the motor. It is also known as "Full
Bridge". Basically there are four switching elements in the H-Bridge as
shown in the figure below.
As you can see in the figure above there are four switching elements named
as "High side left", "High side right", "Low side right", "Low side left".
When these switches are turned on in pairs motor changes its direction
accordingly. Like, if we switch on High side left and Low side right then
motor rotate in forward direction, as current flows from Power supply
through the motor coil goes to ground via switch low side right. This is
shown in the figure below.
Similarly, when you switch on low side left and high side right, the current
flows in opposite direction and motor rotates in backward direction. This is
the basic working of H-Bridge. We can also make a small truth table
according to the switching of H-Bridge explained above.
As already said, H-bridge can be made with the help of transistors as well as
MOSFETs; the only thing is the power handling capacity of the circuit. If
motors are needed to run with high current then lot of dissipation is there. So
head sinks are needed to cool the circuit.
DC Motors
The basic principle of magnetism that like poles repels and opposite
poles attract is the important principle in any working motor. It includes he
property of electromagnets with alternating fields. A simple DC motor
contains a permanent magnet and group of coils which when activated gets
magnetized. The north and south poles of these electromagnets are repelled.
A DC motor is connected to the microcontroller through a motor
driver circuit called L293 driver. Motor will rotate while getting the
instruction from the microcontroller.
To drive a dc motor using a logical IC or a microcontroller interfacing
is necessary since they can’t sufficiently provide enough current for the
motor. Therefore, it can either be turned on using a relay along with its
interfacing circuit. An interface similar to the relay’s interface can be used to
drive a unidirectional motor. This basically consists of a current amplifier.
When a high voltage, dc motor needs to be interfaced, a single transistor
can’t be used i.e. the base is connected to 5V logic. In such a situation a
Darlington pair may be used.
To drive a bidirectional dc motor, it needs an interface which can provide
with the reversal of terminals. In such a case, Darlington pairs/current
amplifiers can be used in H-Bridge configuration.
H-Bridge driver L293D and motor interface with microcontroller
The L293D driver (Pins 2, 7, 10, 15) is connected to P0.0, P0.5, P0.6, P0.7 (Pins 10, 15, 7, 8) respectively. The pins (3, 6) are connected to left motor and pins (11, 14) are connected to right motor.
RS232
The most popular serial communication standard for asynchronous
communications is RS-232 (Recommended Standard – 232. This specifies
the rule of how different connected devices communicate. The connected
devices can either be terminals or communication equipments commonly
referred as DTE & DCE.
According to RS232 interface, it requires only 3 lines i.e. Rx, Tx &
Ground when compared to the bunch of connectors required for parallel
communication. Even though parallel communication is easier to establish,
serial communication is preferred based on the costs for the communication
lines.
The EIA (Electronics Industry Association) RS232C Standard
specifies & suggests a maximum baud rate of 20,000bps, and RS232D is an
advanced version of the same, which allows 1.5 Mbps. The connectors
specified are D-TYPE 25 pin connector and D-TYPE 9 pin connector.
D-Type-
9 pin no.
D-Type-25 pin
no.
Pin outs Function
3 2 RD Receive Data (Serial data input)
2 3 TD Transmit Data (Serial data output)
7 4 RTS Request to send (acknowledge to modem that UART is ready
to exchange data
8 5 CTS Clear to send (i.e.; modem is ready to exchange data)
6 6 DSR Data ready state (UART establishes a link)
5 7 SG Signal ground
1 8 DCD Data Carrier detect (This line is active when modem detects a
carrier
4 20 DTR Data Terminal Ready.
9 22 RI Ring Indicator (Becomes active when modem detects ringing
signal from PSTN
FIGURE 4.1 DB-9 PIN CONNECTOR
According to RS232 specifications, the logic ‘1’ and logic ‘0’ are
called as ‘mark & ‘space’. The signal voltage levels are specified as ‘mark’
should be in the range of -3 to -15 volts and ‘space’ should be in the range of
3 to 15 volts. The modern low power consuming CMOS devices use
different logic levels than the RS232 line specification. The logic levels of
CMOS devices are in the range of 3.3v-5.5v for ‘1’ and -0.3v to 0.8v for ‘0’.
Therefore when communicating with such CMOS/TTL devices, the logic
levels need to be converted
RS232 INTERFACED TO MAX 232
J 2
12345
6789
P 3 . 0
5V
C 4
0 . 1u f
C 7
0 . 1u f
TXD
C 6
0 . 1u f
P 3 . 1
T1O U T
C 11u f
T1O U T
U 3
MAX3232 1516
1 38
1011
1345
26
129
147
GND
VCCR 1 IN
R 2 IN
T2 INT1 IN
C 1+C 1 -C 2+C 2 -
V +V -
R 1O U TR 2O U T
T1O U TT2O U T
C 5
0 . 1u f
R XD
Fig 4.2 RS232 INTERFACED TO MAX232
Rs232 is 9 pin db connector, only three pins of this are used ie 2, 3, 5 the
transmit pin of rs232 is connected to rx pin of microcontroller
MAX232 INTERFACED TO MICROCONTROLLER
.
MAX232 is connected to the microcontroller as shown in the figure above
17, 18 pins are connected to the TX and RX pin i.e. transmit and receive pin
of microcontroller
Power Supply interface with microcontroller
The power supply consists of a 9-0-9 step down transformer. A bridge rectifier is used to rectify and convert AC to DC. A 1000uF capacitor is used to filter the ripples and the output is connected to 7805 voltage regulator. This comprises the power supply for the entire circuit. Vcc is connected to Pin 40 the power supply of microcontroller.
Chapter 4
Software implementation
4.1 RIDE
Please note that in this page RIDE will reference to RIDE6 software
which supports 8051, XA and other derivates. For ARM, ST7 and STM8
family the software is RIDE7.
RIDE is a fully featured Integrated Development Environment (IDE)
that provides seamless integration and easy access to all the development
tools. From editing to compiling, linking, debugging and back to the start,
with a Simulator, ICE, Rom Monitor or other debugging tools, RIDE
conveniently manages all aspects of the Embedded Systems development
with a single user interface.
Fig: RIDE
Multi-file Editor
RIDE is based on a fast multi-document editor designed to meet the
specific needs of programming. The various methods, menus, commands,
and shortcuts are all fully compliant with the Microsoft® specifications for
Windows 2000, XP and NT. Classic commands, such as string search and
block action are integrated. Advanced features such as Matching Delimiter
(parenthesis, brackets), Grep (multi-file search) and Indenter are integrated
as well. The customizable color-highlighting feature is very useful to
indicate specific syntactic elements as they appear in the source file:
keywords, comments, identifiers, operators, and so on. The color-
highlighting feature is automatically keyed to the intrinsic file type (which
means, it works differently for C and assembler).This permits the user to
identify quickly and easily those parts of the code responsible for syntax
errors.
http://www.raisonance.com/products/info/RIDE.php - top
Project Manager:
The project manager creates links between the various files that
includes a project and the tools necessary to create that project. A project is
dedicated to a particular target: 8051, XA, or other microcontrollers. The
linker manages object and library files, and output format conversion as
necessary.
Fig Project Manager
Tree-structured projects ease the management of the most complex
applications (bank switching, flash, multi-processor, multi-module...). The
‘Project Make’ command directs the integrated "make" utility to build or
rebuild the target programs for the current project. To avoid wasting time,
each source file will be translated by its associated tool only if any of its
dependencies are found to be out of date. Dependency analyses, even
directly or indirectly included files, are automatic.
Options can be defined as global (for all the files) or as local (for a specific
node or file). Individual attributes can be set for any file in the project.
Similarities between the different tools make migration from one processor
family to another immediate and easy, permitting multi-processor projects.
http://www.raisonance.com/products/info/RIDE.php-top.
The Message Window and the On-line Help:
The message window displays all warning, error, and progress
messages generated during the processing of files associated with each
project.
Clicking on an error string in the message window automatically positions
the cursor at the point of that error in the source code window.
The Online help system is context-sensitive and provides information
on nearly all aspects of RIDE. A specific help file is supplied with each tool
driven by the IDE ('C' Compiler, Assembler, Linker, and RTOS). Online
menu hints appear on the status line whenever you select a menu command.
Fig Message
http://www.raisonance.com/products/info/RIDE.php-top.
The Script Language:
Most RIDE commands can be run from a script file. Scripts are
written in a C-like language, and are interpreted at execution time. With the
script language, most repetitive tasks can be done automatically thus
speeding up operations and reducing the probability of errors. Scripts are
very useful for Hardware Testing (board, emulator) and to initialize the
system to a known status, but can also be conveniently used for other tasks
such as creating very complex breakpoints or redirecting some output to a
file to run a 'batch' debug session.
http://www.raisonance.com/products/info/RIDE.php-top.
Context Saving:
When a project is closed, the whole associated context is saved (open
file list, window size and position etc.). Settings associated with the
debugger are also saves such as breakpoints, watches etc...
http://www.raisonance.com/products/info/RIDE.php-top
Integrated High-level Debug:
RIDE provides a fully integrated source-level debugging environment.
All information necessary is derived from the translators used to accomplish
each step of the process. This includes mundane aspects such as "path
names", and source code specific information such as details of complex
data types.
With the simple click of a mouse button, the user can select among
several powerful capabilities: simulate, monitor, or emulate. The fast smooth
integration given by RIDE promotes a feeling of familiarity and ease of use,
while providing a level of comfort and efficiency that reduces the most
difficult and complex applications to tasks that are easily managed. This
seamless progression of the "code-translate-link-debug-test" cycle is the
result of perfect communication between the programming tools and the
debugger. This is the heart of RIDE.
Fig : Debugger
Integral Simulation:
RIDE includes simulation engines for most 8051, and XA derivatives.
The simulator/debugger is cleanly integrated into the presentation Windows.
A wide range of 'views' can be selected to provide flexible direct
examination of all memory spaces as well the all internal peripherals. The
simulation engines perform detailed and faithful simulations (including
IDLE or Power down modes), of all peripherals (including interrupt and
watchdog events) present on the selected component.
Advanced Features
RIDE provides a rich variety of 'views' into an application. These
views or windows are associated with control commands like complex
breakpoints or high level trace recording.
http://www.raisonance.com/products/info/RIDE.php - top
4.2 ISP 3.0
Introduction
This ISP Programmer can be used either for in-
system programming or as a stand-alone spi programmer for Atmel
ISP programmable devices. The programming interface is
compatibe
to STK200 ISP programmer hardware so the users of STK200 can also
use the software which can program both the 8051 and AVR series devices.
Hardware
The power to the interface is provided by the target system. The
74HCT541 IC isolates and buffers the parallel port signals. It is necessary to
use the HCT type IC in order to make sure the programmer should also work
with 3V type parallel port.
The printer port buffer interface is same as shown in figure 1.For the
u-controllera40pinZIFsocketcanbe used. This programmer circuit can be
use to program the 89S series devices and the AVR series device switches
are pin compatible to 8051, like 90S8515. For other AVR series devices
the user can make an adapter board for 20, 28 and 40 pin devices. The pin
numbers shown in brackets correspond to PC parallel port connector.
Software
The ISP-30a.zip file contains the main program and the i/o port driver.
Place all files in the same folder. The main screen view of the program is
shown in figure 3.
Also make sure do not program the RSTDISBL fuse in
ATmega8, ATtiny26 and ATtiny2313 otherwise further spi
programming is disable and you will need a parallel programmer to
enable the
spi programming. For the fuses setting consult the datasheet of the
respective device.
For the auto hardware detection it is necessary to short pin 2 and 12 of
DB25connector, otherwise the software uses the default parallel port i.e.
LPT1.
Following are the main features of this software,
Read and write the Intel Hex file.
Read signature, lock and fuse bits.
Clear and Fill memory buffer.
Verify with memory buffer.
Reload current Hex file.
Display buffer checksum.
Program selected lock bits & fuses.
Auto detection of hardware.
Note: The memory buffer contains both the code data and the eeprom
data for the devices which have eeprom memory. The eeprom memory
address in buffer is started after he code memory, so it is necessary the
hex file should contains the eeprom start address after the end of code
memory last address i.e. for 90S2313 the start address for eeprom memory
is 0x800.
The software does not provide the erase command
because th s function is performed automatically during device
programming. If you are required to erase the controller, first use the clear
buffer command then program the controller, this will erase the controller
and also set the AVR device fuses to default setting.
Fig Main screen of the program ISP-Pgm Ver 3.0a
4.3 EMBEDDED ‘C’
Ex: Hitec – c, Keil – c
HI-TECH Software makes industrial-strength software development
tools and C compilers that help software developers write compact, efficient
embedded processor code.
For over two decades HI-TECH Software has delivered the
industry's most reliable embedded software development tools and compilers
for writing efficient and compact code to run on the most popular embedded
processors. Used by tens of thousands of customers including General
Motors, Whirlpool, Qualcomm, John Deere and many others, HI-TECH's
reliable development tools and C compilers, combined with world-class
support have helped serious embedded software programmers to create
hundreds of breakthrough new solutions.
Whichever embedded processor family you are targeting with your
software, whether it is the ARM, PICC or 8051 series, HI-TECH tools and C
compilers can help you write better code and bring it to market faster.
HI-TECH PICC is a high-performance C compiler for the Microchip
PIC micro 10/12/14/16/17 series of microcontrollers. HI-TECH PICC is an
industrial-strength ANSI C compiler - not a subset implementation like some
other PIC compilers. The PICC compiler implements full ISO/ANSI C, with
the exception of recursion. All data types are supported including 24 and 32
bit IEEE standard floating point. HI-TECH PICC makes full use of specific
PIC features and using an intelligent optimizer, can generate high-quality
code easily rivaling hand-written assembler. Automatic handling of page and
bank selection frees the programmer from the trivial details of assembler
code.
Embedded C Compiler
ANSI C - full featured and portable.
Reliable - mature, field-proven technology.
Multiple C optimization levels.
An optimizing assembler.
Full linker, with overlaying of local variables to minimize RAM
usage.
Comprehensive C library with all source code provided.
Includes support for 24-bit and 32-bit IEEE floating point and 32-bit
long data types.
Mixed C and assembler programming.
Unlimited number of source files.
Listings showing generated assembler.
Compatible - integrates into the MPLAB IDE, MPLAB ICD and most
3rd-party development tools.
Runs on multiple platforms: Windows, Linux, UNIX, Mac OS X, and
Solaris.
Embedded Development Environment.
PICC can be run entirely from the. This environment allows you to
manage all of your PIC projects. You can compile, assemble and link your
embedded application with a single step.
Optionally, the compiler may be run directly from the command line,
allowing you to compile, assemble and link using one command. This
enables the compiler to be integrated into third party development
environments, such as Microchip's MPLAB IDE.