Mark Chambers wrote: > >>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
Identical situation to mine (well nearly). Using a 859T CPU, the HPI to a DSP is being investigated and in doing so we've been forcing the DSP to delay TA to the ppc to check that we get an exception but we don't :-(( ME is set in MSR, BME is set in SYPCR, hair gradually disappearing. Guess its more debugging... -- Robin Gilks Senior Design Engineer Phone: (+64)(3) 357 1569 Tait Electronics Fax : (+64)(3) 359 4632 PO Box 1645 Christchurch Email : robin.gilks at tait.co.nz New Zealand ======================================================================= This email, including any attachments, is only for the intended addressee. It is subject to copyright, is confidential and may be the subject of legal or other privilege, none of which is waived or lost by reason of this transmission. If the receiver is not the intended addressee, please accept our apologies, notify us by return, delete all copies and perform no other act on the email. Unfortunately, we cannot warrant that the email has not been altered or corrupted during transmission. =======================================================================
