
PIC18CXX2
DS39026C-page 130
2001 Microchip Technology Inc.
FIGURE 14-8:
I2C SLAVE MODE WAVEFORMS FOR RECEPTION (7-BIT ADDRESS)
FIGURE 14-9:
I2C SLAVE MODE WAVEFORMS FOR TRANSMISSION (7-BIT ADDRESS)
P
9
8
7
6
5
D0
D1
D2
D3
D4
D5
D6
D7
S
A7 A6 A5 A4 A3 A2 A1
SDA
SCL
1
2
3
456
78
9
12
34
56
7
89
12
3
4
Bus Master
terminates
transfer
Bit SSPOV is set because the SSPBUF register is still full.
Cleared in software
SSPBUF register is read
ACK
Receiving Data
D0
D1
D2
D3
D4
D5
D6
D7
ACK
R/W=0
Receiving Address
SSPIF
BF (SSPSTAT<0>)
SSPOV (SSPCON1<6>)
Not ACK
ACK is not sent.
SDA
SCL
SSPIF
BF (SSPSTAT<0>)
CKP (SSPCON1<4>)
A7
A6
A5
A4
A3
A2
A1
ACK
D7
D6
D5
D4
D3
D2
D1
D0
Not ACK
Transmitting Data
R/W = 1
Receiving Address
1
2
3
4
56
789
123
4
5
67
8
9
P
Cleared in software
SSPBUF is written in software
From SSP Interrupt
Service Routine
Set bit after writing to SSPBUF
S
Data in
sampled
SCL held low
while CPU
responds to SSPIF
(the SSPBUF must be written to
before the CKP bit can be set)
R/W = 0