SPxPoll1 cc,aaaa [In]
This instruction results in 1 byte of data being polled out of the peripheral and saved in U(0). There are 16 allowable command codes, so this instruction could address 16 1-byte registers, for example in a 16-digit thumbwheel switch.
This is a low-level instruction associated with the SPLat Expansion Framework. You will most likely never need to know how to use it.