Thanks Bill, Fortunately the XIRQ is routed through programmable logic and I am working on a solution. Andrew ----- Original Message ----- From: tonalbuilder2002 To: Sent: Friday, June 18, 2004 4:43 AM Subject: [68HC12] Re: Non-Maskable Interrupt If I recall correctly from recent experience, the 9S12 XIRQ is low level sensitive only and therefore slightly problematical when connected to an "edge" device...you must be able to return the interrupting signal back high before leaving the XIRQ service routine, otherwise you will saturate the system with XIRQ interrupts as long as the input signal is low. Another point to ponder is that XIRQ comes up disabled out of reset, which seems a bit ironic somehow. Bill Tondreau http://www.kupercontrols.com --- In , "Andrew Lohmann's New Email Server" <andrew.lohmann@b...> wrote: > Hi > Is XIRQ a reasonable substitute for NMI as found on MC6801/HD6301? I can't find a manual to describe it. > > NMI was edge triggered and would interrupt other interrupts. This is handy because I have a high speed data transfer from an analog to digital converter and which uses NMI on the edge of the A/D's busy signal becoming false. Because of the high speed requirement if necessary NMI will interrupt another interrupt currently being handled. > > > Thanks > Andrew Lohmann AIIE > Design Engineer > > PLEASE NOTE NEW EMAIL ADDRESS IS: > andrew.lohmann@b... > > Bellingham + Stanley Ltd. > Longfield Road, Tunbridge Wells, Kent, TN2 3EY, England. > Tel: +44 (0) 1892 500400 > Fax: +44 (0) 1892 543115 > Website: www.bs-ltd.com --------------------To learn more about Motorola Microcontrollers, please visit http://www.motorola.com/mcu o learn more about Motorola Microcontrollers, please visit http://www.motorola.com/mcu ------ Yahoo! Groups Links a.. To |