CSC270 Spring 2016 - Clark Science Center. Thiebaut, Computer Science, Smith College The Motorola 6811 Processor • M68HC11 CPU • 8 Kbytes ROM • 512 Bytes of On-Chip EEPROM •

mith College

Computer Science

Dominique Thiébaut [email protected]

CSC270 Spring 2016Circuits and Systems

Lecture Notes — Week 8

D. Thiebaut, Computer Science, Smith College

Goal


Goal


Goal


Goal


The Motorola 6811 Processor

• M68HC11 CPU • 8 Kbytes ROM • 512 Bytes of On-Chip EEPROM • 256 Bytes of On-Chip RAM • 8-Channel, 8-Bit Analog-to-Digital (A/D) Converter • 38 General-Purpose Input/Output (I/O) Pins


The Motorola 6811 Processor

• M68HC11 CPU • 8 Kbytes ROM • 512 Bytes of On-Chip EEPROM • 256 Bytes of On-Chip RAM • 8-Channel, 8-Bit Analog-to-Digital (A/D) Converter • 38 General-Purpose Input/Output (I/O) PinsSystem On a Chip

(SOC)


The Programmer's View of the 6811


Simplified Architecture


Programmer's View


Complete Architecture


A Sample of 6800 Instructions

http://www.science.smith.edu/dftwiki/images/9/9e/CSC270_Assembly_Instructions.pdf

http://www.science.smith.edu/dftwiki/images/9/9e/CSC270_Assembly_Instructions.pdf


LDAALDAA 0A ; AccA <— Mem[A] (direct)LDAA 0100 ; AccA <— Mem[100](extended)LDAA #3 ; AccA <— 3 (immediate)LDAA X,4 ; AccA <— Mem[X+4](indexed)

LDABLDAB F0 ; AccB <— Mem[F0] (direct)LDAB 0200 ; AccB <— Mem[200](extended)LDAB #3 ; AccB <— 3 (immediate)LDAB X,4 ; AccB <— Mem[X+4](indexed)

LDXLDX #0010 ; X <- 0010 (immediate)


STAA

STAA 00 ; Mem[0] <— AccA (direct)STAA 0000 ; Mem[0] <— AccA(extended)

STAB

STAB 00 ; Mem[0] <— AccB (direct)STAB 0000 ; Mem[0] <— AccB(extended)


ADDA

ADDA 00 ; AccA <— AccA + Mem[0](direct)ADDA 0000 ; AccA <— AccA + Mem[0](extended)ADDA #3 ; AccA <— AccA + 3 (immediate)

ADDB

ADDB 00 ; AccB <— AccB + Mem[0](direct)ADDB 0000 ; AccB <— AccB + Mem[0](extended)ADDB #3 ; AccB <— AccB + 3 (immediate)

ABA

ABA ; AccA <— AccA + AccB (inherent)


INCAINCA ; AccA <— AccA + 1 (inherent)

INCINC 0003 ; Mem[03] <— Mem[03]+1 (extended)

INCBINCB ; AccB <— AccB + 1 (inherent)


JMP

JMP label ; PC <— label (extended)


First 6800-Assembly Program


void main() { char a=2, b=3, result=0; result = a + b; }

ORG 0000a DB 3b DB 4result DB ? ORG 0010start: LDAA a ADDA b STAA result JMP start


Assembling By Hand

http://www.ele.uri.edu/Courses/ele205/6811-Instructions/index.html

ORG 0000a DB 3b DB 4result DB ?

ORG 0010start: LDAA a

ADDA b STAA result JMP start



Assembling By Hand





What can you say about the different

bytes?



We stopped

here last

time…


Side Notes• Motorola 6811 instruction set different from the

Pentium instruction set. Different register sets.

• Different architecture but same groups of instructions (data move, arithmetic and logic, control), and similar addressing modes.

• A note about C, C++, Java and Python programs running on different processors.

• Speed of execution C++, vs Java, vs Assembly http://www.science.smith.edu/dftwiki/index.php/Speed_of_Instructions:_Nasm,_Java,_C%2B%2B_and_Python_comparison


Assembling By Hand







Assembling By Hand







Assembling By Hand







Assembling with an Assembler

Visit this page before continuing…

http://www.science.smith.edu/dftwiki/index.php/CSC270_Assembling_6800_Assembly_Programs_on_OSX/Windows


Assembling with an Assembler




www.science.smith.edu/dftwiki/index.php/CSC270_Assembling_6800_Assembly_Programs_on_OSX/Windows







0000 03 0001 04 0002 00 … 0010 96 0011 00 0012 9B 0013 01 0014 97 0015 02 0016 7E 0017 00 0018 10



ExerciseWrite and assemble a 6800 assembly program that computesy = 2*x + 3, where x and y are byte variables…


Instructions Cycles

http://www.science.smith.edu/dftwiki/images/7/71/6811CycleByCycle.pdfSection 10, Pages 10-6 and 10-13:

http://www.science.smith.edu/dftwiki/images/7/71/6811CycleByCycle.pdf


LDAA 03 ; Acca <— Mem[03] (direct)










Example Program ORG 0000

a DB 0

ORG 0010start: INC a JMP start





Timing DiagramE

R/W'

Address

Data


Observing the Execution with a Scope


You are ready forLab 7!

CSC270 Spring 2016 - Clark Science Center. Thiebaut, Computer Science, Smith College The Motorola 6811 Processor • M68HC11 CPU • 8 Kbytes ROM • 512 Bytes of On-Chip EEPROM •

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