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Hi, Im working with the DSP56303 and Im having trouble when I send data to the port A. If I send, for example, $D12F, and I receive $D21F, or $C52D and I get $C61E. In the same way, the address lines dont match the value I have set up, for example: If I want to write something to the address $007850, in the 16 bits of address lines I get $9403, that I think they are the lowest significant bits of the 24 bit address, other case is: $0F0850 and I get $1A00 I don't know if the DSP in this process changes some bits or, maybe, I have not configure something. If someone has a proved code in assembly and can send it to me, I would thank. See You. Thanks. Hernan Herrera |
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Problems accessing port A in DSP56303
Started by ●March 9, 2004
Reply by ●March 10, 20042004-03-10
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Moin Hernan, I assume you are referring to the external memory interface on Port A, have you properly set the Adress Attribute Registers AAR3-0 ? Note that according to Mot errata you should set all four to a valid (dummy-) address range and SRAM type, and none of them should be set to synchronous SRAM. BCR and also DCR, in case you use DRAM, must be set prior to using Port A. Since you asked for code, here an example of an initialisation I use: movep #$D00439,x:M_AAR1 ; select Flash as in Mot Bootstrap, enable also X/Y access movep #$C00431,x:M_AAR0 ; select USB Chip on $C00000..$CFFFFF movep #$AFBC31,x:M_AAR2 ; CV DAC on x:y:$AFB000...$AFBFFF ($DAC000 not possible here) movep #$B00C31,x:M_AAR3 ; set AA3 to dummy address movep #(WS_DEF<<16)|(WS_DEF<<13)|(WS_DEF<<10)|(WS_FLASH<<5)|WS_USB,x:M_BCR Ciao, Stefan Hernan Dario Herrera wrote: > Hi, > Im working with the DSP56303 and Im having trouble when I send data to the port A. > If I send, for example, $D12F, and I receive $D21F, or $C52D and I get $C61E. > > In the same way, the address lines dont match the value I have set up, for example: If I want to write something to the address $007850, in the 16 bits of address lines I get $9403, that I think they are the lowest significant bits of the 24 bit address, other case is: $0F0850 and I get $1A00 > > > I don't know if the DSP in this process changes some bits or, maybe, I have not configure something. > > If someone has a proved code in assembly and can send it to me, I would thank. > > See You. Thanks. > > Hernan Herrera |
