25.2.3.6.1 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 25-15 and Figure 25-16 are used as a visual reference for this description.

This is a step by step process of what typically must be done to accomplish I2C communication.

  1. Start condition detected.
  2. The Start (S) bit is set; SSPxIF is set if the Start Condition Interrupt Enable (SCIE) bit is set.
  3. Matching address with R/W bit clear is received.
  4. The client pulls SDA low, sending an ACK to the host, and sets SSPxIF bit.
  5. Software clears the SSPxIF bit.
  6. Software reads 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 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 Stop (P) bit, and the bus goes Idle.
Figure 25-15. I2C Client, 7-Bit Address, Reception (SEN = 0, AHEN = 0, DHEN = 0)
Figure 25-16. I2C Client, 7-Bit Address, Reception (SEN = 1, AHEN = 0, DHEN = 0)