SPxChOut cc,aaaa [Out]
<SPX peripheral aaaa, channel cc> << U[0..(V-1)]
This is called the channel out instruction. It results in a variable number of bytes being sent to the peripheral. The data is taken from U starting at U(0). The number of bytes transferred is determined by V, and must be between 0 and 20, unless the firmware was built after 10 Jan 2020, in which case it needs to be less than 250..
There are 16 allowable command codes, so this instruction could address 16 destination registers, for example display lines on a text display. The channel out instruction was designed with LCD displays in mind, but will be useful wherever a variable data length is required or one that is more than 4 bytes long.
The peripheral will respond with a True or a False. This will be saved in U(0).
This is a low-level instruction associated with the SPLat Expansion Framework. You will most likely never need to know how to use it.