;****************************** ;* ;* i2cSend8WACK ;* ;* r1 = data ;* r6 = UcI2CSoftPortA/BCtrl ;* ;* return: ;* ;* r0 = 0 (OK) else other ;* i2cSend8WACK push r1 push r7 push r5 ;76543210 ; ; clk down movei r5,7 ;8 times i2cSend8WACKPushLoop ;DIR OUT, CLK 0 movei r0,$4 extri r1,7 addtqi r0,r0,0 ;set r0 bit 0 = 1 if bit 7 in r1 = 1 gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode moveih r0,$7 ;delay slot nop ;delay slot st r6,r0 ;PUSH ;delay slot nop ;delay slot ;CLK = 1 gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode addi r0,2 ;delay slot nop ;delay slot st r6,r0 ;PUSH ;delay slot nop ;delay slot subi r5,1 brts i2cSend8WACKPushLoop add r1,r1,r1 ;next bit delay slot nop ;delay slot nop ;delay slot nop ;delay slot ;bit send so wait for ack ;DIR IN, CLK 0 movei r0,$0 ;DIR IN, CLK 0 gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode moveih r0,$07 ;EN A delay slot nop ;delay slot st r6,r0 ;PUSH delay slot nop ;delay slot ;push clk high movei r0,$2 ;DIR IN, CLK 1 gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode moveih r0,$07 ;EN A ;delay slot nop ;delay slot st r6,r0 ;PUSH ;delay slot nop ;delay slot ;get result rqldi r6,0 nop movei r1,$8 ld r0 nop and r0,r0,r1 ;r0 = 0 OK, else fail ;clk down again (default) gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode nop ;delay slot nop ;delay slot nop ;delay slot nop ;delay slot movei r1,$0 ;DIR IN, CLK 0 nop moveih r1,$07 ;EN A nop st r6,r1 ;PUSH rqpop rqpop rqpop pop r5 pop r7 pop r1 jmpi r7,0 nop ;delay slot nop ;delay slot nop ;delay slot nop ;delay slot ;****************************** ;* ;* i2cRecive8 ;* ;* r6 = UcI2CSoftPortA/BCtrl ;* ;* return: ;* ;* r0 = data ;* i2cRecive8 push r1 push r7 push r5 movei r0,0 ;76543210 ; ; clk down movei r5,7 ;8 times i2cRecive8PushLoop movei r1,$0 ;DIR IN, CLK 0 gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode moveih r1,$7 ;delay slot nop ;delay slot st r6,r1 ;PUSH ;delay slot nop ;delay slot gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode addi r1,2 ;CLK = 1 ;delay slot nop ;delay slot st r6,r1 ;PUSH ;delay slot nop ;delay slot rqldi r6,0 nop movei r7,$1 ld r1 add r0,r0,r0 ;r0 * 2 lsri r1,3 subi r5,1 brts i2cRecive8PushLoop and r1,r1,r7 ;delay slot nop ;delay slot or r0,r0,r1 ;delay slot add r1,r1,r1 ;next bit ;delay slot nop movei r1,$0 ;DIR IN, CLK 0 gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode moveih r1,$07 ;EN A ;delay slot nop ;delay slot st r6,r1 ;PUSH ;delay slot nop ;delay slot rqpop rqpop rqpop pop r5 pop r7 pop r1 jmpi r7,0 nop ;delay slot nop ;delay slot nop ;delay slot nop ;delay slot ;****************************** ;* ;* i2cSendStart ;* ;* r6 = UcI2CSoftPortA/BCtrl ; i2cSendStart push r0 push r7 movei r0,$7 ;DIR OUT, CLK 1, DATA 1 gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode moveih r0,$07 ;EN A ;delay slot nop ;delay slot st r6,r0 ;PUSH ;delay slot nop ;delay slot movei r0,$6 ;DIR OUT, CLK 1, DATA 0 gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode moveih r0,$07 ;EN A ;delay slot nop ;delay slot st r6,r0 ;PUSH ;delay slot nop ;delay slot rqpop rqpop nop pop r7 pop r0 jmpi r7,0 nop ;delay slot nop ;delay slot nop ;delay slot nop ;****************************** ;* ;* i2cSendStop ;* ;* r6 = UcI2CSoftPortA/BCtrl ; i2cSendStop push r0 push r7 movei r0,$6 ;DIR OUT, CLK 1, DATA 0 gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode moveih r0,$07 ;EN A ;delay slot nop ;delay slot st r6,r0 ;PUSH ;delay slot nop ;delay slot movei r0,$7 ;DIR OUT, CLK 1, DATA 1 gpci r7,2 ;next 4 + X br i2cWaitHalfPeriode moveih r0,$07 ;EN A ;delay slot nop ;delay slot st r6,r0 ;PUSH ;delay slot nop ;delay slot rqpop rqpop nop pop r7 pop r0 jmpi r7,0 nop ;delay slot nop ;delay slot nop ;delay slot nop ;****************************** ;* ;* i2cWaitHalfPeriode ;* i2cWaitHalfPeriode push r0 ;min 134 cycles to waste movei r0,20 ;21 * 6 = 126 (+9 cycles) => 135 nop i2cWaitHalfPeriodeLoop subi r0,1 brts i2cWaitHalfPeriodeLoop nop ;delay slot nop ;delay slot nop ;delay slot nop ;delay slot rqpop jmpi r7,0 nop ;delay slot pop r0 ;delay slot nop ;delay slot nop ;delay slot