Hello, I am doing IDMA reading and writting on an ADSP-2189N, revision 3.2 When writting, which I use for boot up from a host PC via a microcontroller, everything goes fine, which I can verify by means of the 218x-EzICE. But when reading the contents of PM or DM I get strange results, spuriously. The data and code is all in overlay 0, I make sure to do so with an Overlay Latch cycle when writting (the emulator helps me to make sure that it worked). For reading I also set to overlay 0 before writting the starting address from where I want to start reading. But for some accesses the IDDMOVLAY and IDPMOVLAY fields in the IDMA Overlay register change to 0xF or something different than 0x0, so I get wrong results with my readings. I double-checked and no address or overlay latch cycles are being generated, which could cause this strange behavior. IAL is kept low, and /RD is being asserted by the micro as well as /IS, while /WR is clean "1". I reviewed the anomaly list for rev 3.2 and nothing was stated concerning IDMA. I say it again: the trouble arises only for accessing some addresses, in a certain order, but I haven't been able to discover a pattern which I could reproduce and expose here. I am confident that many people here are experts with these chips, like Leon Heller and Al Clark, just to mention two of you. So I hope I can have your valuable advice on how to make my readings bulletproof. Kindest regards, -- Jaime Andr�s Aranguren Cardona jaac@nospam.sanjaac.com SanJaaC Electronics Soluciones en DSP www.sanjaac.com (Remove "nospam" from e-mail address)
ADSP-2189N IDMA
Started by ●November 18, 2004
Reply by ●November 19, 20042004-11-19
Jaime Andr�s Aranguren Cardona wrote:> Hello, > > I am doing IDMA reading and writting on an ADSP-2189N, revision 3.2 When > writting, which I use for boot up from a host PC via a microcontroller, > everything goes fine, which I can verify by means of the 218x-EzICE. > > But when reading the contents of PM or DM I get strange results, spuriously. > The data and code is all in overlay 0, I make sure to do so with an Overlay > Latch cycle when writting (the emulator helps me to make sure that it > worked). For reading I also set to overlay 0 before writting the starting > address from where I want to start reading. But for some accesses the > IDDMOVLAY and IDPMOVLAY fields in the IDMA Overlay register change to 0xF or > something different than 0x0, so I get wrong results with my readings. > >I went crazy debugging my first 21xx design with IDMA until we put series resistors on the control lines. They seem to be _extremely_ sensitive to noise. DH
Reply by ●November 19, 20042004-11-19
Which values, David? TIA -- Jaime Andr�s Aranguren Cardona jaac@nospam.sanjaac.com SanJaaC Electronics Soluciones en DSP www.sanjaac.com (Remove "nospam" from e-mail address)> > > > But when reading the contents of PM or DM I get strange results,spuriously.> > The data and code is all in overlay 0, I make sure to do so with anOverlay> > Latch cycle when writting (the emulator helps me to make sure that it > > worked). For reading I also set to overlay 0 before writting thestarting> > address from where I want to start reading. But for some accesses the > > IDDMOVLAY and IDPMOVLAY fields in the IDMA Overlay register change to0xF or> > something different than 0x0, so I get wrong results with my readings. > > > > > > I went crazy debugging my first 21xx design with IDMA until we put seriesresistors> on the control lines. They seem to be _extremely_ sensitive to noise. > > DH
Reply by ●November 19, 20042004-11-19
Interestingly and strange enough, the same design, with the same microcontroller, gives me good results when reading via IDMA from an ADSP-2188N, same revision (3.2). Will I have to redesign the PCB to include the series resistors? Damn! Thank you, -- Jaime Andr�s Aranguren Cardona jaac@nospam.sanjaac.com SanJaaC Electronics Soluciones en DSP www.sanjaac.com (Remove "nospam" from e-mail address)> > I went crazy debugging my first 21xx design with IDMA until we put seriesresistors> on the control lines. They seem to be _extremely_ sensitive to noise. > > DH