;=======INDIGO4.ASM========================================================= ; radix hex ; list p=16c54 ; c equ 0 z equ 2 dc equ 1 pd equ 3 to equ 4 ;rp0 equ 5 ;No banking on the 'c54 ;rp1 equ 6 ; ; w equ 0 f equ 1 ; ;------------------------------------------------------------------------ indf equ 00 tmr0 equ 01 pcl equ 02 status equ 03 fsr equ 04 porta equ 05 portb equ 06 ;eedata equ 08 ;eeadr equ 09 ;pclath equ 0a ;intcon equ 0b ; ;optreg equ 01 ;trisa equ 05 ;trisb equ 06 ;eecon1 equ 08 ; ;------------------------------------------------------------------------- comflg equ 0008 dlyctr equ 0009 recreg equ 000A recuse equ 000B rloop equ 000C rbit equ 000D xmtreg equ 000E xmtuse equ 000F xloop equ 0010 xbit equ 0011 ; useflg equ 0012 ; ;--------------------------------------------------------------------------- recflg equ 00 lbflg equ 01 feflg equ 02 ndrflg equ 03 roflg equ 04 xmtflg equ 05 xdrflg equ 06 xcflg equ 07 ; outport equ porta outpin equ 01 inport equ porta inpin equ 00 ;---------------------------------------------------------------------------- org 0x1ff goto start org 0x00 ; start clrf porta bsf outport,outpin clrf portb ; bsf status,rp0 ; Not needed for 16c54 movlw 0xFD ; Was 1010.1001 (E9) Now 1111.1101 (FD) ; movwf trisa ; Not needed for 16c54 ; bcf status,rp0 ; Not needed for 16c54 tris porta ; Needed for 16c54 movlw 0x00 ; Set PORTB as outputs tris portb movlw 0xaa ; Put alternating pattern on portb (verify) movwf portb clrf comflg bsf comflg,xcflg goto frec ; Start RECV/XMIT/USER cycle (21/19/12 cycles) ;--------------------------------------------------------------------------- ; include taskfull.grp ;====== TASKFULL.GRP ======================================================= ;------RECEIVE ROUTINE 21 cycles-------------------------------------------- rdeld set rdele ; frec btfss comflg,recflg goto frec2 decfsz rloop,f goto rdelb btfsc comflg,lbflg goto frec3 bsf status,c btfss inport,inpin bcf status,c rrf recreg,f movlw 04 movwf rloop decfsz rbit,f goto rdele btfss comflg,ndrflg bsf comflg,roflg bsf comflg,lbflg movf recreg,w movwf recuse goto rdelf ; frec2 btfsc inport,inpin goto rdela bsf comflg,recflg movlw 08 movwf rbit movlw 05 movwf rloop goto rdelc ; frec3 btfsc inport,inpin goto frec4 bsf comflg,feflg frec4 bcf comflg,recflg bcf comflg,lbflg bsf comflg,ndrflg goto rdeld ; rdelb nop ;rdela goto rda1 ;rda1 goto rda2 ;rda2 goto rdelc rdela nop nop nop nop nop nop nop nop nop nop nop nop nop goto fxmt rdelc nop goto rdele rdele goto rda3 rda3 goto rda4 rda4 goto rdelf ; rdelf ;----TRANSMIT ROUTINE 19 cycles----------------------------------------------------- fxmt btfss comflg,xmtflg goto fxmt2 decfsz xloop,f goto xdlyb movlw 04 movwf xloop decfsz xbit,f goto fxmt4 bcf comflg,xmtflg bsf comflg,xcflg goto xdlyc ; fxmt2 btfss comflg,xdrflg goto xdlya bsf comflg,xmtflg movlw 0a movwf xbit movlw 04 movwf xloop movf xmtuse,w movwf xmtreg bcf comflg,xdrflg goto fxd1 fxd1 bcf outport,outpin nop nop nop nop nop nop nop goto fxmt8 ; ; fxmt4 bsf status,c rrf xmtreg,f ; fxmt5 btfsc status,c goto fxmt6 bcf outport,outpin goto fxmt7 fxmt6 bsf outport,outpin nop fxmt7 nop nop nop nop nop nop nop goto fxmt8 ; ; xdlyc goto fxd4 ; 6 5 fxd4 goto fxd5 ; 4 3 fxd5 nop nop nop nop nop nop nop goto fxmt8 ; 2 1 xdlyb nop ; 20 xdlya nop ; 19 nop ; 18 nop ; 17 nop ; 16 nop ; 15 nop ; 14 nop ; 13 nop ; 12 nop ; 11 nop ; 10 nop ; 9 nop ; 8 nop ; 7 nop ; 6 nop ; 5 nop ; 4 nop ; 3 nop ; 2 nop ; 1 ; fxmt8 ; ;----------------------------------------------------------------------------- ;dloop decfsz dlyctr,f ; goto dloop ; retlw 0 ;----------------------------------------------------------------------------- ; ;------USER ROUTINE 12 cycles------------------------------------------------- echo btfss comflg,ndrflg ; New data received? If yes, skip next goto udlya ; No. Delay and exit movf recuse,w ; Yes, Get received data movwf portb bcf comflg,ndrflg ; Clear new-data received flag uda3 goto frec ;Last line of user udlya nop nop alldun goto frec dloop decfsz dlyctr,f ;3n+5 (includes call statement and return) goto dloop retlw 0 ;----------------------------------------------------------------------- end ;-----------------------------------------------------------------------