PIC18LF24K Datasheet, PDF (359/594 Pages) –

FIGURE 26-16: I²C SLAVE, 7-BIT ADDRESS, RECEPTION (SEN = 0, AHEN = 1, DHEN = 1)
SDA
SCL
S
Master Releases SDA
to slave for ACK sequence
Receiving Address
A7 A6 A5 A4 A3 A2 A1
Receiving Data
ACK _{D7 D6 D5 D4 D3 D2 D1 D0}
12 3 4 56 7 8
91 2 3 45 67 8
ACK
Received Data
D7 D6 D5 D4 D3 D2 D1 D0
91234 5678
Master sends
Stop condition
ACK=1
9
P
SSPxIF
BF
ACKDT
CKP
ACKTIM
If AHEN = 1:
SSPxIF is set
Address is
read from
SSBUF
Slave software
clears ACKDT to
ACK the received
byte
When AHEN=1:
CKP is cleared by hardware
and SCL is stretched
ACKTIM set by hardware
on 8th falling edge of SCL
SSPxIF is set on
9th falling edge of
SCL, after ACK
When DHEN=1:
CKP is cleared by
hardware on 8th falling
edge of SCL
ACKTIM cleared by
hardware in 9th
rising edge of SCL
Cleared by software
Data is read from SSPxBUF
Slave software
sets ACKDT to
not ACK
CKP set by software,
SCL is released
No interrupt
after not ACK
from Slave
ACKTIM set by hardware
on 8th falling edge of SCL
S
P