README
¶
PLEASE NOTE: I no longer actively maintain this project. Pull requests are welcome, but development has halted and issues are unlikely to gain a response.
avr
avr is an implementation of Atmel's AVR microprocessor specification in the Go
programming language.
Note: this package is a work-in-progress. More to come shortly.
Features
- Implements entire AVR instruction set, with the exception of
BREAK,DES,SLEEP,SPMandWDR. - Emulates various hardware modules:
- digital GPIO pins
- timer/counter
- Accurately supports individual MCUs:
- ATtiny4/5/9/10
- ATmega48/88/168
- more to come soon!
Installation
avr is go-gettable:
# go get github.com/kierdavis/avr/cmd/avrem
Usage
The avrem command (in the "cmd" subdirectory) is a command-line interface to
the emulator. To try it out, run it with an Intel HEX file like so:
# avrem program.hex
Flags include -mcu to specify the name of the MCU spec to use, -mcus to list
the names of all available MCU specs, and -freq to specify the execution
frequency.
The "programs" subdirectory contains example programs. Many of these are Arduino programs, and have precompiled IHEX program files for a number of MCUs present in the same directory.
Running the "blink" example for a 16 MHz ATmega168:
# avrem -mcu mega168 -freq 16 programs/blink/blink-atmega168.hex
Note: currently, running the blink program (and probably other programs, when they are added) will produce about 20 "access of unmapped I/O port" warnings. This is simply due to the program initialising hardware subsystems that are not yet implemented in the emulator.
Performance
The maximum unthrottled clock rate approaches 35 MHz on my 2.3 GHz Intel i7 processor. Real AVR microprocessors range from 1 to 20 MHz, so this software can in theory simulate an mid-range AVR processor almost twice as quickly as the physical implementation.
Packages
github.com/kierdavis/avr- miscellaneous shared codegithub.com/kierdavis/avr/clock- manages synchronisation between concurrent processes of emulatorgithub.com/kierdavis/avr/emulator- implementation of CPU emulatorgithub.com/kierdavis/avr/hardware/gpio- implementation of digital GPIO pinsgithub.com/kierdavis/avr/hardware/timer- implementation of timer/counter modulegithub.com/kierdavis/avr/loader/ihexloader- links Intel HEX file parser with loading programs into emulatorsgithub.com/kierdavis/avr/spec- specifications of the many different models of AVR processor (MCUs)
License
This source code is distributed under the MIT license.
Documentation
¶
Index ¶
Constants ¶
const NumInstructions = int(XCH) + 1
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Instruction ¶
type Instruction int8
const ( ADC Instruction = iota ADD ADIW AND ANDI ASR BCLR BLD BRBC BRBS BREAK BSET BST CALL CBI COM CP CPC CPI CPSE DEC DES EICALL EIJMP ELPM_R0 ELPM ELPM_INC EOR FMUL FMULS FMULSU ICALL IJMP IN INC JMP LAC LAS LAT LD_X LD_X_INC LD_X_DEC LD_Y LD_Y_INC LD_Y_DEC LDD_Y LD_Z LD_Z_INC LD_Z_DEC LDD_Z LDI LDS LDS_SHORT LPM_R0 LPM LPM_INC LSR MOV MOVW MUL MULS MULSU NEG NOP OR ORI OUT POP PUSH RCALL RET RETI RJMP ROR SBC SBCI SBI SBIC SBIS SBIW SBRC SBRS SLEEP SPM SPM_2 ST_X ST_X_INC ST_X_DEC ST_Y ST_Y_INC ST_Y_DEC STD_Y ST_Z ST_Z_INC ST_Z_DEC STD_Z STS STS_SHORT SUB SUBI SWAP WDR XCH )
func (Instruction) IsTwoWord ¶
func (inst Instruction) IsTwoWord() bool
func (Instruction) String ¶
func (i Instruction) String() string
Source Files
Directories
¶
| Path | Synopsis |
|---|---|
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cmd
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avrmakedec
avrmakedec is a tool to emit an efficient AVR instruction decoder from a specification of the binary syntax of the instruction set.
|
avrmakedec is a tool to emit an efficient AVR instruction decoder from a specification of the binary syntax of the instruction set. |
|
automatically generated by avrmakedec -output decode_gen.go -pkg emulator -kind lutc DO NOT EDIT
|
automatically generated by avrmakedec -output decode_gen.go -pkg emulator -kind lutc DO NOT EDIT |
|
hardware
|
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gpio
Package gpio implements a general purpose digital I/O port.
|
Package gpio implements a general purpose digital I/O port. |
|
timer
Package gpio implements a timer/counter unit.
|
Package gpio implements a timer/counter unit. |
|
loader
|
|
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ihexloader
Package ihexloader encapsulates loading of IHEX files into an Emulator.
|
Package ihexloader encapsulates loading of IHEX files into an Emulator. |