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| | | PicPuter 2.0 : Appendix A : AutoConfig Script |
The Auto Config Script allows you to change the default value of any variable at reset. It can be used to change the default baud rate, configurator value, or even to support a different crystal frequency.
At reset, but before interrupts are turned on, picputer looks at location $201 to get the address of the configuration script. You can modify this location to point to your own autoconfig script in $1000 to $1FFF or simply modify the existing script in place.
The script starts at $07e8 for version 1.80
Modifying the autoconfig script may make your PicPuter unbootable. If this happens use the bootloader to re-flash the default program. If you happen to be a registered user and use my serial bootloader, your key will be preserved. If you use another method you will have to reregister you PicPuter using your key.
 AutoConfig Script Rules |
Every script starts with its size in its first word.
All locations $00-$1F and $80-$9F are directly writable.
The flash value is 14 bits wide. The lower 8 bits are the value to write. The upper 6 bits are the address to write, where the upper bit number 13 is promoted to the most significant bit to access $80-$9F
The remaining registers $20-$7F and $B0-$FF can be modified by using the INDF ($00) and FSR ($04) registers.
If you write to $00 (INDF) the location specified by $04 (FSR) is modified.
If you write to $80 (technically also INDF) the location specified by (FSR OR $80) is modified to easily edit the upper bits of a 16 bit variable.
| PicPuters Default AutoConfig Script Commented |
ORG 0x07E8
AUTO_CONFIG_SCRIPT:
;$07E8
DA 0X0017 ; SIZE
;$07E9 - 0
DA 0x3F82 ; ADCON1=$82 SET adc left justified
;$07EA
DA 0X253F ; TRISA=3F
DA 0X2601 ; TRISB=01
DA 0X2790 ; TRISC=90
DA 0X2800 ; TRISD=00
DA 0X0400+INPUT_FSR ; WRITE THE INPUT BUFFER
DA INPUT_BUFFER ;
;$07E0 - 7
DA 0x3900 + _BAUD_ ; SET BAUD RATE
DA 0X325f ; PR2 = _TICK_
DA 0X0400+TICKS_PER_HUNDREDTH ; FSR = TICKS_PER_HUNDREDTH
DA _TICKS_PER_HUNDREDTH_ ; WRITE LO
;$07E4
DA 0X1D0F ; CCP2CON = 0x0F ; usage led
DA 0X170F ; CCP1CON = 0x0F ; volts
DA 0X1530 ; CCPR1L = 0x30 ; default contrast
DA 0X046F ; FSR = Configurator
;$07E8
DA CONFIG_INIT ; WRITE LO
DA 0X2000+CONFIG_HI_INIT ; WRITE HI
DA 0X0440 ; FSR = PC
DA 0X00FF ; PC(LOW) = $FF
DA 0X20FF ; PC(HI) = $FF
DA 0x121C ; T2CON=$1C
DA 0x2C02 ; PIE2 TMR2IE
DA 0x0BC0 ; INTCON=C0 ; Enable Interupts
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