Lint is an effective tool, but it can only catch errors that it can see at assembly time. That is it won't check for errata that might involve say DMA and core contention. However, any type of "stall" should be caught. Also, in the case of a stall it is best to either use that information to re-order your code for optimization or simply leave it alone and allow the processor to insert the stall for you. The latter can actually lead to faster execution as a stall of an entire clock period (the equivalent of a NOP) may not be required. As for the original question if it's not a violation of an errata I see no reason a NOP should be required... -- dB --- Alexander Trica <motorola@moto...> wrote: > gusflit wrote: > > > The INSERT syntax being > > > > insert #CO,S,D ;where #CO is the control word, S the register > from > > ;where the bits are pickep up, and D the result > > ;accumulator where those bits are inserted. > > > > If i don't place a NOP before transfering the accumulator into > > memory, i get impredictible results. > > Hi Gustave, > > did you try the lint563.exe tool? It is part of the Suite56 package. > It > should put out some warnings when there are problems due to > pipelining. > > Well, how ever - sometimes the assembler puts out a warning and the > lint563 tool not. But the lint563 tool seems to find more of the > "pipelining-insert-nop-problems" than the assembler. > > Which dsp of the 563xx series are you using? > > insert #CO,S,D > > nop ;this nop seems to be compulsory > > move D,x:datacell > > Well, may be it is some kind of read-write stall - like > > move #CO,D > move D,x:datacell > > would cause a pipelining stall. How ever, the assembler realizes that > > kind of pipelining stall and puts out a warning. I also read > something > about that the dsp would insert a NOP by it self, but ... you never > know. :) I always put in NOPs by my self. > > regards > Alex > Yahoo! Mail Stay connected, organized, and protected. Take the tour: http://tour.mail.yahoo.com/mailtour.html

gusflit wrote: > The INSERT syntax being > > insert #CO,S,D ;where #CO is the control word, S the register from > ;where the bits are pickep up, and D the result > ;accumulator where those bits are inserted. > > If i don't place a NOP before transfering the accumulator into > memory, i get impredictible results. Hi Gustave, did you try the lint563.exe tool? It is part of the Suite56 package. It should put out some warnings when there are problems due to pipelining. Well, how ever - sometimes the assembler puts out a warning and the lint563 tool not. But the lint563 tool seems to find more of the "pipelining-insert-nop-problems" than the assembler. Which dsp of the 563xx series are you using? > insert #CO,S,D > nop ;this nop seems to be compulsory > move D,x:datacell Well, may be it is some kind of read-write stall - like move #CO,D move D,x:datacell would cause a pipelining stall. How ever, the assembler realizes that kind of pipelining stall and puts out a warning. I also read something about that the dsp would insert a NOP by it self, but ... you never know. :) I always put in NOPs by my self. regards Alex

Dear Gustave, Have you checked the errata for the derivative that you are using? Such as it is there should be no need for a NOP because, as you say, the processor will insert an arithmetic stall. If you are forced to insert an additional one I'd be tempted to say there is an errata. Regards, -- Henk-Piet Glas Support Engineer ----------------------- E-mail: support.nl@supp... 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 ]------

Hi to all, I've just finished some assembler code for the DSP563xx family. I used for the first time the INSERT instruction, and noticed the following behaviour: The INSERT syntax being insert #CO,S,D ;where #CO is the control word, S the register from ;where the bits are pickep up, and D the result ;accumulator where those bits are inserted. If i don't place a NOP before transfering the accumulator into memory, i get impredictible results. insert #CO,S,D nop ;this nop seems to be compulsory move D,x:datacell If i remove the nop instruction, the assembler program won't report a pipeline stall. Can anyone negate/confirm that the instruction isn't handled properly by both the assembler and the processor? (normally the processor should insert automatically a nop and the assembler should report a pipeline stall). Regards, Gustave