Knowledge Base

Sets the clock rate and clock polarity for subsequent SPx and SPiceX transfers. The argument m determines the combination according to the following table:

mClock rate (Approx)Clocks on edge ..
01.8MHzFalling
1920kHzFalling
2230kHzFalling
358kHzFalling
41.8MHzRising
5920kHzRising
6 (default)230kHzRising
758kHzRising

In general, falling edge clocking suits peripherals with a microprocessor and rising edge clocking suits peripherals with hardware shift registers.

This is a low-level instruction associated with the SPLat Expansion Framework. You will most likely never need to know how to use it unless you need to implement systems with more than about 70 I/O points. There is also a tutorial on SPiceX.

This instruction is not available on any 32-bit boards prior to Dialect 30, and will only be available on those few boards that explicitly implement it.