PIC16LF1824T39A_12 Datasheet, PDF (255/418 Pages) Microchip Technology – 20-Pin Flash Microcontrollers with XLP Technology

25.5.4 SLAVE MODE 10-BIT ADDRESS
RECEPTION
This section describes a standard sequence of events
for the MSSP1 module configured as an I²C slave in
10-bit Addressing mode.
Figure 25-20 is used as a visual reference for this
description.
This is a step by step process of what must be done by
slave software to accomplish I²C communication.
1. Bus starts Idle.
2. Master sends Start condition; S bit of
SSP1STAT is set; SSP1IF is set if interrupt on
Start detect is enabled.
3. Master sends matching high address with R/W
bit clear; UA bit of the SSP1STAT register is set.
4. Slave sends ACK and SSP1IF is set.
5. Software clears the SSP1IF bit.
6. Software reads received address from
SSP1BUF clearing the BF flag.
7. Slave loads low address into SSP1ADD,
releasing SCL.
8. Master sends matching low address byte to the
Slave; UA bit is set.
Note: Updates to the SSP1ADD register are not
allowed until after the ACK sequence.
9. Slave sends ACK and SSP1IF is set.
Note: If the low address does not match, SSP1IF
and UA are still set so that the slave soft-
ware can set SSP1ADD back to the high
address. BF is not set because there is no
match. CKP is unaffected.
10. Slave clears SSP1IF.
11. Slave reads the received matching address
from SSP1BUF clearing BF.
12. Slave loads high address into SSP1ADD.
13. Master clocks a data byte to the slave and
clocks out the slaves ACK on the 9th SCL pulse;
SSP1IF is set.
14. If SEN bit of SSP1CON2 is set, CKP is cleared
by hardware and the clock is stretched.
15. Slave clears SSP1IF.
16. Slave reads the received byte from SSP1BUF
clearing BF.
17. If SEN is set the slave sets CKP to release the
SCL.
18. Steps 13-17 repeat for each received byte.
19. Master sends Stop to end the transmission.
PIC16LF1824T39A
25.5.5 10-BIT ADDRESSING WITH ADDRESS
OR DATA HOLD
Reception using 10-bit addressing with AHEN or
DHEN set is the same as with 7-bit modes. The only
difference is the need to update the SSP1ADD register
using the UA bit. All functionality, specifically when the
CKP bit is cleared and SCL line is held low are the
same. Figure 25-21 can be used as a reference of a
slave in 10-bit addressing with AHEN set.
Figure 25-22 shows a standard waveform for a slave
transmitter in 10-bit Addressing mode.
 2012 Microchip Technology Inc.
Preliminary
DS41657A-page 255