28.5.2.1 7-Bit Addressing Reception

This section describes a standard sequence of events for the MSSP module configured as an I2C client in 7-bit Addressing mode. Figure 28-14 and Figure 28-15 are used as a visual reference for this description.

This is a step-by-step process of how to accomplish I2C communication.

  1. Start bit detected.
  2. The S bit is set; SSPxIF is set if interrupt on Start detect is enabled.
  3. Matching address with the R/W bit clear is received.
  4. The client pulls SDA low sending an ACK to the host, and sets the SSPxIF bit.
  5. Software clears the SSPxIF bit.
  6. Software reads the received address from SSPxBUF, clearing the BF flag.
  7. If SEN = 1, client software sets the CKP bit to release the SCL line.
  8. The host clocks out a data byte.
  9. Client drives SDA low sending an ACK to the host, and sets the SSPxIF bit.
  10. Software clears SSPxIF.
  11. Software reads the received byte from SSPxBUF, clearing BF.
  12. Steps 8-12 are repeated for all received bytes from the host.
  13. Host sends Stop condition, setting the P bit, and the bus goes Idle.