include ; This program is a serial programmer for a 9366 serial EEPROM with a microwire ; interface. This program accepts Motorola SRecords via the serial interface ; and programs the EEPROM with the downloaded data. This program acceepts 3 ; types of SRecords: ; ; S1 - program data ; S9 - release target reset and EEPROM interface so that target can execute. ; SR - Special: read and display the contents of the EEPROM ; This program was designed as a serial downloader for compiled tokens for my ; NPCI interpreter. For more information on NPCI, consult my PIC page at: ; ; http://www.finitesite.com/d3jsys ; ; LICENSE: This software can be used, modified, and redistributed for personal ; non-commercial use only. Please contact the author at byron@cc.gatech.edu ; for any commercial usage of this software. d1 equ .12 eecomm equ .12 ; d2 equ .13 eebits equ .13 count equ .14 type equ .15 copyhi equ .15 addrhi equ .16 addrlo equ .17 byte equ .18 copylo equ .18 eecount equ .19 count2 equ .20 buf equ .28 ; target board defines. Note a eedata2 is a combined data in and data out line ; for the EEPROM. The data out line must be tied to the data in line via a ; resistor. 1K should be fine. cs equ .0 clk equ .1 eedata2 equ .2 reset equ .3 start movlw .255 movwf PORTA clrf PORTB clrw tris PORTB ; Turn port B to all outputs movlw 0x11 tris PORTA ; Turn port A to all except for RA4 and RA0 main call serin xorlw 'S' btfss STATUS,Z goto main ; Loop forever call serin movwf type xorlw '0' btfss STATUS,Z goto test1 clrf PORTB ; Reset everything. clrw tris PORTB ; Make port B all outputs again. ok movlw 'Y' call serout goto main test1 movf type,W xorlw '1' btfss STATUS,Z goto test9 call getbyte movwf count call getbyte movwf addrhi call getbyte movwf addrlo movlw buf movwf FSR movlw .3 subwf count,W movwf count2 movwf count incf count,F ; Get the checksum too. fillit call getbyte movwf INDF incf FSR,F decfsz count,F goto fillit ; At this point the buffer is full of bytes to write to the EEPROM and ; count2 has the count of the bytes. ; ; Remember to do EWEN and EWDS before and after writing. call ewen ; enable the EEPROM movlw buf ; start of buffer movwf FSR wrloop movf INDF,W ; Get the next byte to write call eewrite ; Write it. incfsz addrlo,F ; Next address goto wrcont incf addrhi,F wrcont incf FSR,F decfsz count2,F ; Write all the bytes goto wrloop call ewds ; disable writing on the EEPROM clrf PORTB ; Disable the EEPROM goto ok ewen movf addrlo,w ; Need bit 7. so copy this movwf copylo ; movf addrhi,w ; Need this too movwf copyhi movlw 0xff movwf addrlo movwf addrhi movlw 0x90 call eeaddr ; Run the command and return movf copylo,w ; Restore addresses movwf addrlo ; movf copyhi,w ; movwf addrhi return ewds movf addrlo,w ; Need bit 7. so copy this movwf copylo ; movf addrhi,w ; Need this too movwf copyhi clrf addrlo clrf addrhi movlw 0x80 call eeaddr ; Run the command and return movf copylo,w ; restore address movwf addrlo ; movf copyhi,w ; movwf addrhi return test9 movf type,W xorlw '9' btfss STATUS,Z goto testR ; Normally would release reset so that program can start running. ; Be sure to make the CS, CLK, and DI bits (0-2) inputs before executing. movlw 'Y' ; Send a Y back... call serout movlw .15 ; tris PORTB ; Make CS, CLK, DI/DO, and reset inputs ; This releases the reset on the target. debug btfss PORTA,0 ; See if a start bit from host goto main ; Exit if start bit found btfss PORTB,clk ; Check for clock HI. goto debug ; Loop of no rising edge btfsc PORTB,cs ; Debugging only when CS is not selected goto debug ; Loop until then ; At this point this is debugging info for us. Get 8 bits and ship up ; to the host. dbgin movlw .8 ; Number of bits to get movwf d2 dbloop btfss PORTB,clk ; Wait for the clock to be HI goto dbloop btfsc PORTB,eedata2 ; Get the bit. xfer to carry goto dbset bcf STATUS,C goto dbcont dbset bsf STATUS,C dbcont rrf d1,F ; Shift bit into destination dbloop2 btfsc PORTB,clk ; Wait for the clock to go low goto dbloop2 decfsz d2,F goto dbloop movf d1,W ; Get the data call serout ; and ship it off to the host goto debug testR movf type,W ; Read the contents of the EEPROM xorlw 'R' btfss STATUS,Z goto main call getbyte ; Get the address to start reading movwf addrhi call getbyte andlw 0xf0 ; Make sure on 16 byte boundry movwf addrlo call crlf ; Print a CR/FC combo. clrf eecount ; Clear the count rloop movf eecount,W andlw .15 ; Test only low 4 bits xorlw .0 ; See if 0 btfsc STATUS,Z ; Skip address printing if not on 16 byte call prtaddr ; Print the address call eeread ; read the EEPROM call putbyte movlw ' ' call serout incfsz addrlo,F goto rcont1 incf addrhi,F rcont1 incfsz eecount,F goto rloop call crlf call serin xorlw 'q' btfsc STATUS,Z goto main goto rloop ascbyte andlw .15 addwf PCL,F retlw '0' retlw '1' retlw '2' retlw '3' retlw '4' retlw '5' retlw '6' retlw '7' retlw '8' retlw '9' retlw 'A' retlw 'B' retlw 'C' retlw 'D' retlw 'E' retlw 'F' ; The eeaddr call expects the command (plus A8) in the top nybble of W ; The lower 8 address are retrieved from addrlo eeread movlw 0xc0 ; Read commmand (SB 1 0) btfsc addrhi,0 ; Check A8 iorlw 0x10 ; Light A8 in the eecommand call eeaddr ; Send out the address movlw TRISB ; Get portb data direction movwf FSR bsf INDF,eedata2 ; Make data bit incoming movlw .8 ; Number of bits to read movwf eebits eerloop bsf PORTB,clk ; Clock in the next bit nop btfsc PORTB,eedata2 ; Get the bit. xfer to carry goto eerset bcf STATUS,C goto eercont eerset bsf STATUS,C eercont bcf PORTB,clk ; Bring the clock low. rlf byte,F ; Shift bit into destination decfsz eebits,F goto eerloop bcf INDF,eedata2 ; Make data outgoing again clrf PORTB ; Make all bits low. movf byte,W ; Get the result return ; And return it. eewrite movwf byte ; store the byte to write. movlw 0xa0 ; Read commmand (SB 0 1) btfsc addrhi,0 ; Check A8 iorlw 0x10 ; Light A8 in the eecommand call eeaddr ; Send out the address movlw .8 ; Number of bits to write. Last bit is special movwf eebits eewloop rlf byte,F ; Put the next bit in the carry btfsc STATUS,C ; Get the bit. xfer to carry goto eewset bcf PORTB,eedata2 goto eewcont eewset bsf PORTB,eedata2 nop eewcont bsf PORTB,clk ; Clock in the next bit movlw .1 ; See if last bit xorwf eebits,W btfss STATUS,Z ; See if last bit was clocked in goto eewcon2 bcf PORTB,cs ; Drop CS before dropping clock on last bit nop ; delay between successive port writes eewcon2 bcf PORTB,clk ; Bring the clock low. decfsz eebits,F goto eewloop movlw .4 ; Get portb data direction tris PORTB ; Make data an input bsf PORTB,cs ; Turn on CS again to check status. nop eewbusy btfss PORTB,eedata2 ; Get status goto eewbusy ; loop until not busy clrw tris PORTB nop clrf PORTB ; Make all bits low. return ; And return eeaddr bcf PORTB,cs ; Turn the EEPROM on for one blip. nop nop bsf PORTB,cs ; Turn the EEPROM on movwf eecomm ; Save the command movlw .4 ; Number of bits to shift movwf eebits movlw .2 ; number of times to execute eealoop movwf count eealoop rlf eecomm,F ; Put the next bit in Carry btfsc STATUS,C ; check the carry bit goto eeaset1 bcf PORTB,eedata2 goto eeacon1 eeaset1 bsf PORTB,eedata2 nop eeacon1 bsf PORTB,clk ; Clock the bit into the EEPROM nop bcf PORTB,clk ; Bring the clock low. decfsz eebits,F goto eealoop ; Do all 4 command bits decfsz count,F ; Are we done? goto eealow ; Nope. got to do low addresses return ; Yes. Yes we are done. CS remains raised. eealow movf addrlo,W ; shift out the low part of the address movwf eecomm ; Put in the command register movlw .8 ; Number of bits to shift movwf eebits goto eealoop ; Shift out low address bits too. crlf movlw .13 ; CR call serout movlw .10 ; LF goto serout ; Print and return. prtaddr call crlf movf addrhi,W call putbyte movf addrlo,W call putbyte movlw ':' call serout movlw ' ' goto serout ; Print and return serin movlw .8 ; Number of bits to get movwf d2 sbit btfsc PORTA,0 ; Wait for a start bit goto sbit call halfdel ; delay half a bit btfsc PORTA,0 ; Make sure it wasn't a glitch goto sbit siloop call delay ; Wait for center of next cell btfsc PORTA,0 ; Get the bit. xfer to carry goto siset bcf STATUS,C goto sicont siset bsf STATUS,C sicont rrf d1,F ; Shift bit into destination decfsz d2,F goto siloop call halfdel ; delay into stop bit. ; Have whole stop bit to do work. movf d1,W ; Get return value return serout movwf d1 ; Save the character. movlw .8 ; 8 bits to transmit movwf d2 bcf PORTA,3 ; Send the start bit call delay soloop rrf d1,F ; Get the next bit into the carry btfss STATUS,C ; check the carry bit goto soclr bsf PORTA,3 ; Set bit to 1 goto socont soclr bcf PORTA,3 socont call delay decfsz d2,1 goto soloop bsf PORTA,3 ; Stop bit call delay return delay clrf TMR0 ; Start at timer 0 dloop movlw .192 ; Comparing to 192 andwf TMR0,W ; Mask off lower bits xorlw .192 ; See if equal to 192 btfss STATUS,Z goto dloop ; loop 'til then return ; That's all. halfdel clrf TMR0 ; Start at timer 0 hdloop movlw .97 ; Comparing to 96 andwf TMR0,W ; Mask off lower bits xorlw .97 ; See if equal to 96 btfss STATUS,Z goto hdloop ; loop 'til then return ; That's all. putbyte movwf byte swapf byte,W ; Get the high nybble call ascbyte ; Get ascii value call serout movf byte,W ; Get low nybble call ascbyte goto serout getbyte call serin ; Get top nybble call convert ; Convert it to hex movwf byte ; Save it. call serin ; get the second nybble call convert ; And convert it too swapf byte,F ; Move the top nybble to proper position iorwf byte,W ; Merge nybbles return ; All done. convert movwf d1 ; Save temp. I know it already there but I ; Want this routine to function standalone. movlw '0' ; value to subtract subwf d1,F ; Remove offset movlw .10 ; See if larger than 9 subwf d1,W btfss STATUS,C ; Positive. Must be A-F goto condone movlw .7 ; Further offset removed subwf d1,F condone movf d1,W ; Put result in W return ; And begone END