> On Wed, 2004-12-08 at 05:15, Robin Gilks wrote: > > Greetings > > > > Any Freescale lurkers out there? > > > > The mpc866 manual implies that if the internal core times out an > > external Transfer Acknowledge bus signal (by exerting the internally > > generated Transfer Error Acknowledge signal) an exception is generated. > > > > I've tried extending the external TA signal well beyond 2040 clock > > cycles the maximum timeout allows and I see the busses start up again > > (indicationg that they are no longer waiting) but I don't see anything > > on TEA and I don't get an exception thrown. > > > > Any clues? Manual error?, silicon error?, my brain error? > > Did you enable the bus monitor in the SYPCR register? >
You've also got to have ME set in MSR to get the exception. For whatever it's worth, I have an mpc852 design (part of 866 family) that uses external acknowledge and it works as advertised. I've seen the acknowledger, a DSP, fail, and we get a machine check exception. (I've never looked at TEA, though). Mark Chambers
