29.6.7.4 Typical Receive Sequence:

  1. The user generates a Start condition by setting the SEN bit.
  2. SSPxIF is set by hardware on completion of the Start.
  3. SSPxIF is cleared by software.
  4. The user writes SSPxBUF with the client address to transmit and the R/W bit set.
  5. Address is shifted out the SDA pin until all eight bits are transmitted. Transmission begins as soon as SSPxBUF is written to.
  6. The MSSP module shifts in the ACK bit from the client device and writes its value into the ACKSTAT bit.
  7. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPxIF bit.
  8. The user sets the RCEN bit and the host clocks in a byte from the client.
  9. After the eighth falling edge of SCL, SSPxIF and BF are set.
  10. The host clears SSPxIF and reads the received byte from SSPUF which clears BF.
  11. The host sets the ACK value to be sent to client in the ACKDT bit and initiates the ACK by setting the ACKEN bit.
  12. Host’s ACK is clocked out to the client and SSPxIF is set.
  13. The user clears SSPxIF.
  14. Steps 8-13 are repeated for each received byte from the client.
  15. The host sends a not ACK or Stop to end communication.
Figure 29-29. I2C Host Mode Waveform (Reception, 7-Bit Address)