list p=16F887, w=-302 include __config _CONFIG1,0xE0E4 __config _CONFIG2,0xF8FF #define bSCL 3 #define bSDA 4 org 0 init BANKSEL TRISC movlw (1 << bSCL) | (1 << bSDA) movwf TRISC CLRF TRISD BANKSEL PORTD CLRF PORTD init_i2c BANKSEL SSPSTAT MOVLW B'10000000' ;100 kHz, MOVWF SSPSTAT MOVLW 0x31 ;20MHz --> 100kHz | 20000/(4*100)-1 MOVWF SSPADD clrf SSPCON2 BANKSEL SSPCON MOVLW B'00101000' ;PORTC SCL, SDA I2C LÁBAK, MASTER MODE MOVWF SSPCON BCF PIE1,SSPIE BCF INTCON,PEIE BCF INTCON,GIE BCF PIR1,SSPIF ;INTERUPT JELZŐBIT TÖRLÉSE, HOGY BIZTOS MŰKÖDJÖN: START/STROP/ACK BANKSEL SSPCON I2CByteWrite call I2CBSTART ; start i2c movlw 0xA0 ; cím, rw bit 0 - A szimulátorban a chip címe 1010 000-ra lett állítva call I2CTX ; küldés ;---------------- movlw 0x00 ; cím call I2CTX movlw 0x00 ; cím call I2CTX ;---------------- movlw 0xEE ; adat call I2CTX ; küldés call I2CBSTOP ; stop I2CByteRead call I2CBSTART ; start i2c movlw 0xA0 ; cím, rw bit 0 - A szimulátorban a chip címe 1010 000-ra lett állítva call I2CTX ; küldés ;---------------- movlw 0x00 ; cím call I2CTX movlw 0x00 ; cím call I2CTX ;---------------- bcf PIR1,SSPIF ; Clear SSP interrupt flag bsf STATUS,RP0 ; Select Bank1 bsf SSPCON2,RSEN ; restart i2c call I2Cbstop_wait0 movlw 0xA1 ; cím, rw bit 1 - A szimulátorban a chip címe 1010 000-ra lett állítva call I2CTX ; küldés ; Read data byte bcf PIR1,SSPIF ; Clear SSP interrupt flag bsf STATUS,RP0 ; Select Bank1 bsf SSPCON2,ACKDT ; Select to send NO ACK bit bsf SSPCON2,RCEN ; Initiate reception of byte call I2Cbstop_wait0 ; Wait for oparation completed movf SSPBUF,W ; Copy byte to WREG bcf PIR1,SSPIF ; Clear SSP interrupt flag bsf STATUS,RP0 ; Select Bank1 bsf SSPCON2,ACKEN ; Generate ACK/NO ACK bit call I2Cbstop_wait0 ; Wait for oparation completed movwf PORTD goto I2CByteWrite I2CTX bcf PIR1,SSPIF ; Clear SSP interrupt flag movwf SSPBUF ; Write byte out to device I2Cbstop_wait0 ; Wait for oparation completed bcf STATUS,RP0 ; Select Bank 00 bstop_wait btfss PIR1,SSPIF ; Check if operation completed goto bstop_wait ; If not, keep checking return I2CBSTART bcf STATUS,RP1 ; Select Bank 0x bcf STATUS,RP0 ; Select Bank 00 bcf PIR1,SSPIF ; Clear SSP interrupt flag bsf STATUS,RP0 ; Select Bank 01 bsf SSPCON2,SEN ; Generate Start condition goto I2Cbstop_wait0 I2CBSTOP bcf PIR1,SSPIF ; Clear SSP interrupt flag bsf STATUS,RP0 ; Select Bank 01 bsf SSPCON2,PEN ; Generate Stop condition goto I2Cbstop_wait0 END