PicoBlaze CPLD Microcontroller

PicoBlaze CPLD Microcontroller

Quick Start Training

Agenda

• What is PicoBlaze• PicoBlaze operation• PicoBlaze software flow• Customize PicoBlaze• Memory integration• Why PicoBlaze


What is PicoBlaze?

• A fully customizable 8-bit soft microcontroller macros that provides – 49 16-bit instructions– 8 general-purpose 8-bit registers– 256 directly and indirectly addressable ports– Reset and a maskable interrupt


PicoBlaze Block Diagram

Interrupt Control

8OUT_PORT8 Registers 8-bit

Program Flow

Control

ZERO & CARRY Flags

ALU

Interrupt Flag Store

Program Counter

Program Counter

Stack

8

8

8

8

Operational Control & Instruction Decoding

8PORT_IDPort

Address Control

READ_STROBEWRITE_STROBE

INTERRUPT

8 8ADDRESS

8

RESET

CLK

16INSTRUCTION

8

8

8

8IN_PORT

CONSTANT DATA


PicoBlaze Operation

INSTRUCTION[15:0]

ADDRESS[7:0]

CLK

IN_PORT[7:0]

INTERRUPT

RESET

INSTRUCTIOIN[15:0]ADDRESS[7:0]

OUT_PORT[7:0]PORT_ID[7:0]

READ_STROBE

WRITE_STROBE

CLK

PicoBlaze

Program ROM

CLK

ADDRESS(7:0) 00 00 01 02 03 04

INSTRUCTION(15:0) 0700 0700 0801 F632 DC5A

RESET

2 clock cycle operation


PicoBlaze Instruction Set• Program Control

Group– JUMP– CALL– RETURN

• Logical Group– LOAD– AND– OR– XOR

• Arithmetic Group– ADD– ADDCY– SUB– SUBCY

• Shift & Rotate Group– SR0– SR1– SRX– SRA– RR– SL0– SL1– SLX– SLA– RL

• Input/Output Group– INPUT– OUTPUT

• Interrupt Group– RETURNI ENABLE– RETURNI DISABLE– INTERRUPT ENABLE– INTERRUPT DISABLE


Assembler

• A simple DOS executable file• Written in C• Use Microsoft Visual Studio 6.0• Easy to change


Assembler FilesFilename.asm

ASM.EXE

Filename.mcs Filename.vhd

Filename.bin

Filename.fmt

Filename.log

<User input file>

<VHDL for simulation>

<Binary code in hex format>

<Formatted assembly file>

<Assembler report>

<Binary code for ROM>


A Simple Shifter

Constant shifter_port, 04 ;declare port

Namereg s7, shifter_reg ;declare register

Loop1: Load shifter_reg, 01 ;init shifter reg

Loop2: Output shifter_reg, shifter_port

SL0 shifter_reg ;shift left with 0

Jump NZ, loop2 ;goto loop2 when s7<>0

Jump loop1 ;goto loop1


Shifter Program

Address Hex Binary

00 0701 0000011100000001

01 8F04 1000111100000100

02 A706 1010011100000110

03 D501 1101010100000001

04 D000 1101000000000000

Load s7, 01

Output s7, 04

SL0 s7

Jump NZ, 01

Jump 00


PicoBlaze Software Flow

• Compile PicoBlaze source– Use WebPACK 5.2i or later– Use FISE 5.2i or later

• Assemble the program code– asm filename.asm

• Download to the CPLD– iMPACT 5.2i or later

• Download assembled object code to EEPROM


Making a Processor Change• Add an instruction

– Modify picoblaze.vhd– Add a constant with instruction code:

constant new_instruction_id : std_logic_vector(4 downto 0) := “10101";– Add instruction decoding signal

i_new_instruction <= '1' when instruction(15 downto 11) = new_instruction_id else '0';

– Define VHDL component with functionality of new instruction – Add new component to picoblaze.vhd

• Tweak the assembler– Add new instruction to asm.cpp

char *new_instruction_id = “10101“;– Add case to write_program_word function of asm.cpp– Recompile asm.cpp to create asm.exe


Making a Processor Change

• A DSP example - bit reversal (“Flip”) operation

• 12 to 18 instructions needed in regular microcontroller programming

• A newly created FLIP function in PicoBlaze can be used to complete the operation in just one instruction cycle

A B C D E F G H

H G F E D C B A


Macrocell Usage


Program Memory Integration

• Binary code and processor can be integrated into a single CPLD

• Eliminates external PROM• SOC solution• Reduces size• Increases performance


Integration Design Flow• Assemble the design

– Use PicoBlaze Assembler– asm design.asm– Generates design.vhd

• Write top level VHDL– Wrap picoblaze.vhd and design.vhd (output from assembler)

• Compile top level VHDL source– Use WebPACK 5.2i or later– Use FISE 5.2i or later

• Download to CPLD– Use iMPACT 5.2i or later


1 + 1 < 2

Macrocells Product Terms Registers FB Inputs Fmax

212/256 ( 83%) 642 /896 ( 72%) 155/256 ( 61%) 451/640 ( 70%) 30 MHz

Macrocells Product Terms Registers FB Inputs Fmax

107/256 ( 42%) 341 /896 ( 38%) 82 /256 ( 32%) 208/640 ( 32%) 87 MHz

PicoBlaze

PicoBlaze + Shifter

- Fitter removes redundant circuits


PicoBlaze Demonstration

• Demonstrate simple shifter• Add FLIP instruction

– Exchanges bits in specified register• MSB to LSB• LSB to MSB

– Modify picoblaze.vhd– Create FLIP component– Modify asm.cpp

• Demonstrate FLIP instruction with new program


Why Use PicoBlaze?

• Emulate out of production processors• Lower power consumption than older small processors• Customizable for performance

– PicoBlaze runs faster than most 8-bit and16-bit uCs (PICs, 8051, 6811, 80188, 6816, etc.)

• Customizable for specific applications– uCs have fixed features– uCs have fixed instructions sets– PicoBlaze can run functions quickly in parallel logic


Why Use PicoBlaze?

• PicoBlaze is parameterized– uCs have fixed size– uCs have limited I/Os

• Can be reconfigured “On the Fly (OTF)”• Cryptography/security


Conclusion

• PicoBlaze is a soft microcontroller module• Use PicoBlaze for custom microcontroller

applications• Create custom instruction sets• Program memory integration• Use PicoBlaze Assembler• Compile with current Xilinx software


CoolRunner-II Reference DesignsApplication Reference Design

Reference Number

Lanaguage MacrocellTarget Device

% Utilizated

XPATH Module Design XAPP356 VHDL 225 XC2C384 588 Channel DVM Springboard XAPP146 Pocket C, VHDL 184 XC2C256 71Springboard Module Design XAPP147 Pocket C, VHDL 67 XC2C128 52

8051 Microcontroller Interface XAPP349 VHDL 57 XC2C64 89SPI XAPP348 VHDL 135 XC2C256 52

IrDA and UART XAPP345 VHDL or Verilog 87 XC2C128 67UARTS XAPP341 VHDL or Verilog 61 XC2C128 47

I2C Bus Controller XAPP333 VHDL or Verilog 131 XC2C256 51

N x N Crosspoint Switch XAPP380 VHDL 193 XC2C256 75SMBus Controller XAPP353 VHDL 158 XC2C256 61

Encoder Manchester Encoder/Decoder XAPP339 VHDL or Verilog 55 XC2C64 85Decoder 16b/20b Encoder/Decoder XAPP336 VHDL 76 XC2C128 59

Error Detection & Correction XAPP383 VHDL 66 XC2C128 52NAND Interface XAPP354 VHDL or Verilog 9 XC2C32 28

Wirless Wireless Transciever XAPP358 VHDL 156 XC2C256 60Consumer MP3 Player XAPP328 VHDL 225 XC2C256 88

PDA

Memory

Datacom

Free HDL CoolRunner-II design code download:http://www.xilinx.com/products/xaw/coolvhdlq.htm


Appendix A

• Instruction set descriptions– Syntax– Bit description


Program Syntax• No blank lines – Use a semicolon for blank lines

• Comments – Any item on a line following a semicolon (;)

• Constant – Must be specified in the form of a 2 digit hexadecimal value(00 – FF)

• Line Labels – To identify a program line for JUMP or CALL instruction should be followed by a colon (:)

• CONSTANT Directive – Assigns an 8-bit constant value to a label

• NAMEREG Directive – Assigns a new name to any of the 8 registers

• ADDRESS Directive – Forces the following instructions commencing at a new address value


Program Control

I I I I I C C C A A A A A A A A

1 1 0 1 01 1 0 1 11 0 0 1 0

JUMP

CALL

RETURN

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

01

Unconditional

Conditional

Address

0 00 11 01 1

if Zero

if NOT Zero

if Carry

if NOT Carry

JUMP aa

JUMP Z, aa

JUMP NZ, aa

JUMP C, aa

JUMP NC, aa

CALL aa

CALL Z, aa

CALL NZ, aa

CALL C, aa

CALL NC, aa

RETURN

RETURN Z

RETURN NZ

RETURN C

RETURN NC

Instruction syntax


Interrupt Control

I I I I I 0 0 0 0 0 0 0 0 0 0 C

INTERRUPT

RETURNI

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

01

Enable

Disable

1 1 1 1 0

1 0 1 1 0Don’t Care

INTERRUPT ENABLE

INTERRUPT DISABLE

ENABLE INTERRUPT

DISABLE INTERRUPT

Instruction syntax


Logical Operation

I I I I I X X X Y Y Y K K K K K15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Constant

sX sY

0 C 0 0 00 C 0 0 10 C 0 1 00 C 0 1 1

LOAD sX, C

AND sX, C

OR sX, C

XOR sX, C

01

K

sY

LOAD sX, KK

AND sX, KK

OR sX, KK

XOR sX, KK

LOAD sX, sY

AND sX, sY

OR sX, sY

XOR sX, sY

Instruction syntax


Arithmetic Operation

I I I I I X X X Y Y Y K K K K K15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Constant

sX sY

0 C 1 0 00 C 1 0 10 C 1 1 00 C 1 1 1

ADD sX, C

ADDCY sX, C

SUB sX, C

SUBCY sX, C

01

K

sY

ADD sX, KK

ADDCY sX, KK

SUB sX, KK

SUBCY sX, KK

ADD sX, sY

ADDCY sX, sY

SUB sX, sY

SUBCY sX, sY

Instruction syntax


SHIFT/ROTATE

1 0 1 0 0 X X X 0 0 0 0 C D D D15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

sX 01

L - Left

R - Right

Instruction

1 1 01 1 10 1 00 0 01 0 0

SR0/SL0

SR1/SL1

SRX/SLX

SRA/SLA

RR/RL

1 0 1 0 1 0 1 0

1 0 1 0 1 0 1 0

Carry

SR0 sX

SR1 sX

SRX sX

SRA sX

RR sX

SL0 sX

SL1 sX

SLX sX

SLA sX

RL sX

Instruction syntax


Input/Output Control

I I I I I X X X Y Y Y P P P P P15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Constant PORT_ID

sX sY01

P

sY

Input

Output

1 C 0 0 0

1 C 0 0 1

INPUT sX, PP

INPUT sX, sY

OUTPUT sX, PP

OUTPUT sX, sY

Instruction syntax

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PicoBlaze CPLD Microcontroller