Hi,

I'm fiddling about with I2C for the first time, so please feel free to point
out any errors or pitfalls I should watch out for.

I understand that after a START condition has been initiated, the SSPIF flag
should be raised in PIR1, but it's not happening for me. The code I'm using
is below - basically, I call INIT_I2C, followed by START_I2C. The latter
never returns because WAIT_I2C doesn't get past its internal loop.

What's wrong?

Thanks,

Kieran

--

INIT_I2C
    MOVLW   0x28                ; Select I2C Master Mode
    MOVWF   SSPCON

    BSF     STATUS, RP0         ; Select bank 1
    CLRF    SSPCON2
    BCF     SSPSTAT, SMP        ; Set slew rate and I2C levels
    BCF     SSPSTAT, CKE
    MOVLW   0x3F                ; Bits 6 to 0 are loaded into the baud rate
    MOVWF   SSPADD              ;  generator - max value is 63 (3F) - gives
                                ;  300k clock at 20MHz
    BCF     STATUS, RP0         ; Select bank 0

    RETURN


START_I2C
    BSF     STATUS, RP0         ; Select bank 1
    BSF     SSPCON2, SEN        ; Initiate START condition
    BCF     STATUS, RP0         ; Select bank 0

    CALL    WAIT_I2C            ; Wait for START condition to complete

    RETURN


WAIT_I2C
    BTFSS   PIR1, SSPIF         ; Wait for the SSPIF flag to appear
    GOTO    WAIT_I2C

    BCF     PIR1, SSPIF         ; Clear the interrupt and continue
    RETURN


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