AVRdis manual

AVRdis is a Free disassembler, published under the rules of the GPL. It was started in order to get familiar with the AVR opcodes and processors and to test the (then) new Mocka 0608m compiler. Both targets were met. AVRdis proved to be a reliable and flexible disassembler that will meet any processor related to the Atmel AVR line.
AVRdis consists of two parts:

AVRdis is based upon processor specific configuration files. These files have names which are as specific as possible and they are stored in one specific directory on the filesystem: "/usr/local/AVR". The layout of the files is as follows:

Keyword	Does
FLASH	The amount of Flash ROM on the AVR processor, measured in 8 bit bytes, even though the processor treats it's Flash memory as 16 bit words. This was done to remain compatible with Atmel datasheets.
EEPROM	The number of bytes of EEPROM data space on the AVR processor.
SRAM	The amount of bytes in the on board static RAM chip. Note, that this is the raw number, as mentioned on the datasheet. In practice there will be less bytes, since the SRAM overlaps the processor registers and ports.
PORTS	A list of port numbers and port names.
BITS	A list with port names, followed by (unambiguous) bit-names. Each line must have 9 entries: The port name (case sensitive) as it appears in the list above Bit 7 name Bit 6 name Bit 5 name Bit 4 name Bit 3 name Bit 2 name Bit 1 name Bit 0 name The bit names are all uppercase. If a bit is not defined, it is represented by a dash ('-').
COMPILER	A set of parameters that are processor specific, but not used by AVRdis.

The sections 'PORTS', 'BITS' and 'COMPILER' are similar to 'compound statements': their end needs to be marked by the keyword 'END'. If the END is missing, the outcome of the configuration process is not defined.

Configuration files are named after their target processor. For the Atmel AT90S8515, the file is called 'AT90S8515', simple as that. Please keep in mind that Unix is case sensitive. So there is a big difference between entering 'atMEGA16' and 'ATmega16'. The way Atmel calls their processors today (October 2006) is decisive.

This file contains the processor specific data for the disassembler system. Target processor : ATmega8515 Author : Jan Verhoeven E-mail : jan272@gmail.com Date : October 14, 2006 BEGIN FLASH 8192 EEPROM 512 SRAM 512 PORTS 04 OSCCAL 05 PINE 06 DDRE 07 PORTE 08 ACSR 09 UBRRL 0A UCSRB 0B UCSRA 0C UDR 0D SPCR 0E SPSR 0F SPDR 10 PIND 11 DDRD 12 PORTD 13 PINC 14 DDRC 15 PORTC 16 PINB 17 DDRB 18 PORTB 19 PINA 1A DDRA 1B PORTA 1C EECR 1D EEDR 1E EEARL 1F EEARH 20 UBRRH/UCSRC 21 WDTCR 24 ICR1L 25 ICR1H 28 OCR1BL 29 OCR1BH 2A OCR1AL 2B OCR1AH 2C TCNT1L 2D TCNT1H 2E TCCR1B 2F TCCR1A 30 SFIOR 31 OCR0 32 TCNT0 33 TCCR0 34 MCUCSR 35 MCUCR 36 EMCUCR 37 SPMCR 38 TIFR 39 TIMSK 3A GIFR 3B GICR 3D SPL 3E SPH 3F SREG END BITS ACSR ACD ACBG ACO ACI ACIE ACIC ACIS1 ACIS0 UCSRB RXCIE TXCIE UDRIE RXEN TXEN UCSZ2 RXB8 TXB8 UCSRA RXC TXC UDRE FE DOR PE U2X MPCM SPCR SPIE SPE DORD MSTR CPOL CPHA SPR1 SPR0 SPSR SPIF WCOL - - - - - SPI2X EECR - - - - EERIE EEMWE EEWE EERE UCSRC URSEL UMSEL UPM1 UPM0 USBS UCSZ1 UCSZ0 UCPOL WDTCR - - - WDCE WDE WDP2 WDP1 WDP0 TCCR1B ICNC1 ICES1 - WGM13 WGM12 CS12 CS11 CS10 TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 FOC1A FOC1B WGM11 WGM10 SFIOR - XMBK XMM2 XMM1 XMM0 PUD - PSR10 TCCR0 FOC0 WGM00 COM01 COM00 WGM01 CS02 CS01 CS00 MCUCSR - - SM2 - WRDF BORF EXTRF PORF MCUCR SRE SRW10 SE SM1 ISC11 ISC10 ISC01 ISC00 EMCUCR SM0 SRL2 SRL1 SRL0 SRW01 SRW00 SRW11 ISC2 SPMCR SPMIE RWWSB - RWWSRE BLBSET PGWRT PGERS SPMEN TIFR TOV1 OCF1A OCF1B - ICF1 - TOV0 OCF0 TIMSK TOIE1 OCIE1A OCIE1B - TICIE1 - TOIE0 OCIE0 GIFR INTF1 INTF0 INTF2 - - - - - GICR INT1 INT0 INT2 - - - IVSEL IVCE SREG I T H S V N Z C END COMPILER END END

All bits in the port register file of the Atmel AVR line of processors have names. Most of them are extreme abbreviations of the role they play in the processor architecture. But some of the names are less descriptive than their actual bitnumber. Two examples below: