ECE 447: Lecture 5

Software Development

ECE 447: Software Abstraction Layers

High-level language (C, C++, Pascal, Fortran)

Assembly language (68HC11, 8051, Z80)

Machine language

assembler

compiler

linker

Object code

ECE 447: Software Abstraction Layers

C Pascal

Intermediate Code

68HC11 8051 Z80

Objectcode

compiler

assembler

Machinelanguage

Objectcode

Machinelanguage

Objectcode

Machinelanguage

linker

ECE 447: Assembly Characteristics

1. Very hardware dependent

2. Not very portable (if at all)

3. Very detailed (responsible for all register contents)

4. No inherent data types

5. Requires programming discipline

6. Non-intuitive, requires clear documentation

7. Access to all hardware intricacies of the chip

8. Fastest execution

9. Less memory

ECE 447: Assembly language vs. machine code

Assembly language

[label] mnemonic [operands]

LDAA #$4ALDAA $5B, Y

Machine code

$86 $4A

[prebyte] opcode [operands]

$18 $A6 $5B

START CLRA

$4F

ECE 447: Machine Code for 68HC11

Number of instructions represented using a single-byte opcode

Number of instructions represented using a combination prebyte+opcode

76

236

Values of prebytes

18, 1A, CD

ECE 447: Software Cycle

Text editor

Cross-assembler m6811-elf-as

Cross-compiler m6811-elf-gcc

Assembly source

C source

Relocatable object

Relocatable object

Linkerm6811-elf-ld(m6811-elf-gcc) Linker

command fileUser libraries

libraries

Non-relocatableexecutable program

memory.x

.s.c

.o.o

(a.out)

{lib_name}.a

Objectlisting .lst

{lib_name}.a

ECE 447: Software Cycle

Non-relocatableexecutable image

Downloadable file converter :m6811-elf-objcopy

Downloadable file

a.out

a.s19

ECE 447: Motorola S-Record Format

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……………………………….S112FFC700000000000000000000000000000027S123FFD6C02FC02FC02FC02FC02FC02FC02FC02FC02FC02FC02FC02FC02FC02FC02FC02F17S10DFFF6C02FC02FC02FC02FC00081S9030000FC

ECE 447: Motorola S-Records

S108C000C601F7103D2C

Data bytecount

Recordtype

Loadaddress

Databytes

Checksum

S9030000FC

Recordtype

Data bytecount

Startaddress

Checksum