Embedded Systems Design ICT 5307. Embedded System What is an embedded System??? Any IDEA???

Embedded Systems DesignICT 5307

Embedded System Replacement for discrete logic-based circuits

Provide functional upgrades

Provide easy maintenance upgrades

Improves mechanical performance

Protection of intellectual property

Replacement for analogue circuits

Analog Signal Processing

Digital Signal Processing

Digital Signal Processing Analogue signals have infinite values between

Their working range range.

Digital signal processors represents the infinite variations with a finite number of steps / values

Low pass filter roll-off◦ 16 bit word length => 90 dB◦ 24 bit word length => 120 dB

Embedded System Processor

Memory

Peripherals◦ Binary outputs◦ Serial outputs◦ Analogue values◦ Displays◦ Time derived outputs

Software

Embedded System Software

◦ Initialization and configuration◦ Operating system or run-time environment◦ The applications software itself◦ Error handling◦ Debug and maintenance support.

Algorithms

Motorola MC68HC705C4A

Data Processors

The larger data size was needed to help support higher precision arithmetic

The increased address space was needed to support bigger blocks of memory for larger programs

The complex instruction was needed to help reduce the amount of memory required to store the program

Data Processors

Pipelining Instruction◦ Instruction fetching◦ Decoding◦ Execution

Pipelining stalls◦ Branching

Data Processors

Intel Pentium

Reduced instruction set computing (RISC)

The 80/20 rule

All instructions will be executed in a single cycle (sometimes multiple cycles may be needed)

Memory will only be accessed via load and store instructions

All execution units will be hardwired with no microcoding

The Berkeley RISC model

Sun SPARC RISC processor

The ARM RISC architecture Currently 50+ manufacterers

Standard RISC architecture techniques◦ Load-store architecture◦ Simple addressing modes based on register contents and instruction information◦ fixed length instructions (4 byte word)

Register banking

Special registers:◦ Register 14: Link register◦ Register 15: Program counter◦ Register 13: Stack pointer

The ARM processing modes

Digital Signal Processors

Example:◦ FIR filter

◦ Sampled data◦ Coefficients◦ Multiplication and addition

Motorola DSP56000

Marks Distribution

Mid 1 – 5th / 6th week – 30%

Mid 2 – 9th / 10th week - 30%

Final – After 14th week – 40%

Processor Selection