Hi Steve,
Ok, I've intepreted "The initial content of the remaining general purpose registers is undefined." as being undefined after power on, and not at every thread start.
I'm interfacing to a Homeplug chip with a GPSI interface using 2 SPI's. The XGATE can handle the transmit/receive interrupt fine, but I also tried to calculate the 32 bit CRC while transmitting. Because I have only 2 XGATE interrupts running, it seemed possible to keep the 32 bit intermediate results and some pointers in the XGATE registers (when the XGATE becomes idle after RTS).
I'm using a S12XDP512 with XGATE V2, for now I let the S12 calculate the CRC before transmitting and maybe I will switch to an S12 with XGATE V3 so a receive interrupt maybe handled while calculating the CRC....
Thanks.