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Hello, I'm using a 56321, and I think I need to enable Stack extension (I'm getting unpredictable behavior in an interrupt that can be 'fixed' by reducing the nesting level of DOR loops). I've looked all over for a simple example of how to correctly enable stack extension, and I can't seem to find one. Can anyone here point me to a source? Thanks in advance, Steve |
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Stack Extension..
Started by ●December 3, 2004
Reply by ●December 3, 20042004-12-03
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Steve, Essentially you just need to ensure that the stack size (SZ) and extension pointer (EP) registers are configured and that you've selected X or Y memory space before enabling stack extension... -- dB --- Steve Kellogg <> wrote: > Hello, > > I'm using a 56321, and I think I need to enable Stack extension (I'm > getting unpredictable behavior in an interrupt that can be 'fixed' by > > reducing the nesting level of DOR loops). > I've looked all over for a simple example of how to correctly enable > stack extension, and I can't seem to find one. Can anyone here point > > me to a source? > Thanks in advance, > Steve __________________________________ |
Reply by ●December 6, 20042004-12-06
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Dear Steve, We use the following strategy: (1) extern F_lc_ub_se (2) extern F_lc_ue_se (3) move #F_lc_ub_se+2,ep (4) move #(F_lc_ue_se-(F_lc_ub_se+2))/2+14,sz (5) bset #16,OMR (6) bset #20,OMR In here (1) and (2) are begin/end locator labels for the extension stack. (3) concerns a workaround for silicon bug ES6. (4) Initialises the stack size register according the 56300 family manual. (5) sets the space in which extension stack resides (in this case Y space). (6) enables the stack extension mechanism. Regards, -- Henk-Piet Glas Support Engineer ----------------------- E-mail: Altium Software BV Voice: +31-33-455 85 84 Saturnus 2 Fax: +31-33-455 55 03 3824 ME Amersfoort WWW: http://www.altium.com The Netherlands --------[Altium - Making Electronics Design Easier]-------- |
