Following an ACK if
the R/W bit is set, a read request, the slave hardware will clear CKP. This
allows the slave time to update SSPxBUF with data to transfer to the master. If the SEN
bit is set, the slave hardware will always stretch the clock after the ACK sequence. Once the slave is ready; CKP is set by software and communication resumes.
Important:
- 1.The BF bit has no effect on whether or not the clock will be
stretched. This is different than previous versions of the module that would not
stretch the clock, clear CKP, if SSPxBUF was read before the ninth falling edge of
SCL.
- 2.Previous versions of the module did not stretch the clock for
a transmission if SSPxBUF was loaded before the ninth falling edge of SCL. It is now
always cleared for read requests.