INIT: bsf STATUS,RP0 ; Bank1 movlw 0xFF movwf TRISC ; All input clrf SSPSTAT ; Disable SMBus inputs bsf SSPSTAT,SMP ; Disable slew rate control movlw 0x31 ; Divide FOSC/4 by .50 (FOSC=.20000000Hz) movwf SSPADD ; Setup 100 kHz I2C clock clrf SSPCON2 ; Clear control bits bsf STATUS,RP1 ; Bank3 ifdef __16F886 movlw 0x0F ; Only RA3, 2, 1, 0 analogue endif movwf ANSEL clrf ANSELH endif bcf STATUS,RP0 ; Bank2 bcf STATUS,RP1 ; Bank0 movlw b'00101000' movwf SSPCON ; Enable SSP, select I2C Master mode return ;****************************************************************************** ; I2C RTC functions ;****************************************************************************** InitTime ; Init time from I2C RTC movlw RTC_Second ; Address of Seconds ; tddH = 0x02 call I2CByteReadSetAddr; Read seconds call BcdToBin movwf Second2 addwf Second2,f ; tddH = 0x03 call I2CByteRead ; Read minute call BcdToBin movwf Minute ; tddH = 0x04 call I2CByteRead ; Read hour call BcdToBin3F ; Mask format and AM/PM movwf Hour ; tddH = 0x05 call I2CByteRead ; Read day call BcdToBin3F movwf Day swapf tdd,f rrf tdd,f rrf tdd,w andlw 0x03 movwf dotindex ; Save year bit 1..0 ; tddH = 0x06 call I2CByteRead ; Read Month andlw 0x1F call BcdToBin movwf Month swapf tdd,f rrf tdd,w andlw 0x07 movwf WDay ; tddH = 0x07 movlw RTC_Year ; Address of Year call I2CByteReadSetAddr; Read year movwf Year return StoreTime movlw 0x80 ; Disable counting command call SendRtcCmd ; tddH = 0x01 incf tddH,f ; Address of seconds ; tddH = 0x02 bcf STATUS,C ; Store Second rrf Second2,w call I2CBcdWrite ; tddH = 0x03 movf Minute,w ; Store Minute call I2CBcdWrite ; tddH = 0x04 movf Hour,w ; Store Hour call I2CBcdWrite ; tddH = 0x05 swapf Year,w ; Store Day and Year bit 1..0 movwf tdd rlf tdd,f rlf tdd,f movlw 0xC0 andwf tdd,f movf Day,w call BCDIorI2CWrite ; tddH = 0x06 swapf WDay,w ; Store Month and Wday movwf tdd rlf tdd,f movlw 0xE0 andwf tdd,f movf Month,w call BCDIorI2CWrite ; tddH = 0x07 movlw 0x00 ; Enable counting command call SendRtcCmd ; tddH = 0x01 StoreYear movlw RTC_Year ; Address Year movwf tddH ; tddH = 0x10 movf Year,w call I2CByteWrite ; tddH = 0x11 comf tdd,w call I2CByteWrite ; tddH = 0x12 movf Century,w goto I2CByteWrite BCDIorI2CWrite call Conv2BCD iorwf tdd,w goto I2CByteWrite SendRtcCmd clrf tddH ; tddH = 0x00 goto I2CByteWrite ; Only tdd and tddH used in MSSP I2C routines ;*******************Start bit subroutine************************** ; This routine generates a Start condition ; (high-to-low transition of SDA while SCL ; is still high. ;***************************************************************** I2CBSTART bcf PIR1,SSPIF ; Clear SSP interrupt flag bsf STATUS,RP0 ; Select Bank 01 bsf SSPCON2,SEN ; Generate Start condition goto I2Cbstop_wait0 ;*******************Restart bit subroutine************************** ; This routine generates a Repeated Start ; condition (high-to-low transition of SDA ; while SCL is still high. ;***************************************************************** I2CBRESTART bcf PIR1,SSPIF ; Clear SSP interrupt flag bsf STATUS,RP0 ; Select Bank 01 bsf SSPCON2,RSEN ; Generate Restart condition goto I2Cbstop_wait0 ;*******************Data transmit subroutine********************** ; This routine transmits the byte of data ; stored in w to the I2C serial ; device. ;***************************************************************** I2CTX bcf PIR1,SSPIF ; Clear SSP interrupt flag movwf SSPBUF ; Write byte out to device goto I2Cbstop_wait0 ; Wait for oparation completed ;*******************Byte read test subroutine********************* ; This routine tests the byte read feature ; of the I2C serial device. It will read ; 1 byte of data at address I2CAddress from the device. ;***************************************************************** I2CByteReadSetAddr movwf tddH I2CByteRead call I2CBSTART ; Generate Start condition ; Send control byte movlw RTC_ADDR & 0xFE ; Load control byte for write call I2CTX ; Send control byte to device movf tddH,w ; Get address call I2CTX ; Send address to device call I2CBRESTART ; Generate Restart condition ; Send control byte movlw RTC_ADDR | 0x01 ; Load control byte for read call I2CTX ; Send control byte to device ; Read data byte bcf PIR1,SSPIF ; Clear SSP interrupt flag bsf STATUS,RP0 ; Select Bank 01 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 Bank 01 bsf SSPCON2,ACKEN ; Generate ACK/NO ACK bit call I2Cbstop_wait0 ; Wait for oparation completed movwf tdd ; Save data ;*******************Stop bit subroutine*************************** ; This routine generates a Stop condition ; (low-to-high transition of SDA while SCL ; is still high. ;***************************************************************** I2CBSTOP incf tddH,f ; Move address bcf PIR1,SSPIF ; Clear SSP interrupt flag bsf STATUS,RP0 ; Select Bank 01 bsf SSPCON2,PEN ; Generate Stop condition I2Cbstop_wait0 bcf STATUS,RP0 ; Select Bank 00 bstop_wait btfss PIR1,SSPIF ; Check if operation completed ifdef DebugI2C return else goto bstop_wait ; If not, keep checking endif return ;*******************Byte write test subroutine******************** ; This routine tests the byte write feature ; of the I2C serial device. ;***************************************************************** I2CBcdWrite call Conv2BCD I2CByteWrite movwf tdd ; Store data call I2CBSTART ; Generate Start condition movlw RTC_ADDR & 0xFE ; Load control byte for write call I2CTX ; Send control byte to device movf tddH,w ; Get address call I2CTX movf tdd,w ; Get data call I2CTX ; Send data byte to device goto I2CBSTOP ; Generate Stop condition