Datasheet

PIC16F72X/PIC16LF72X
DS41341E-page 170 © 2009 Microchip Technology Inc.
FIGURE 17-3: SPI MASTER MODE WAVEFORM
EXAMPLE 17-1: LOADING THE SSPBUF (SSPSR) REGISTER
SCK
(CKP = 0
SCK
(CKP = 1
SCK
(CKP = 0
SCK
(CKP = 1
4 Clock
Modes
Input
Sample
Input
Sample
SDI
bit 7
bit 0
SDO
bit 7
bit 6
bit 5 bit 4
bit 3
bit 2
bit 1 bit 0
bit 7
bit 0
SDI
SSPIF
(SMP = 1)
(SMP = 0)
(SMP = 1)
CKE = 1)
CKE = 0)
CKE = 1)
CKE = 0)
(SMP = 0)
Write to
SSPBUF
SSPSR to
SSPBUF
SDO
bit 7
bit 6
bit 5 bit 4
bit 3
bit 2
bit 1 bit 0
(CKE = 0)
(CKE = 1)
BANKSEL SSPSTAT ;
LOOP BTFSS SSPSTAT, BF ;Has data been received(transmit complete)?
GOTO LOOP ;No
BANKSEL SSPBUF ;
MOVF SSPBUF, W ;WREG reg = contents of SSPBUF
MOVWF RXDATA ;Save in user RAM, if data is meaningful
MOVF TXDATA, W ;W reg = contents of TXDATA
MOVWF SSPBUF ;New data to xmit