Gary, Do you have the 'FREE' bit set in the McBSP? This determines the functionality of the McBSP under emulation. What you want is the FREE bit set to 1. This will allow the serial port to keep clocking while the CPU is halted. You don't need to worry about the EDMA as it will keep running while the emulator is halted by default. I think what may be happening is that the halting is causing the EDMA and McBSP to lose sync. FREE and SOFT bits are explained in the Peripheral Reference Guide (spru 190d, pg.12-8). The FREE bit is bit 25 of the Serial Port Control Register (SPCR). Andrew --- In c6x@y..., Jeff Brower <jbrower@s...> wrote: > Gary- > > >OK, I guess I'm still at the low-level software problems stage. I could > >live with the JTAG approach not being able to transfer large amounts of data > >to visualise on a host. What is really stopping me getting on is not being > >able to modify a single memory location without interrupting the EDMA > >receiving data. I also thought that both the HPI and the JTAG interfaces > >(once they are inside the DSP) both use the EDMA ? Surely the JTAG should > >be able to perform transfers of small amounts of data (single words) in just > >as efficient a manner as the HPI ?? > > Except that with JTAG the processor has to be stopped temporarily. Maybe that > is what messes up EDMA? Maybe you miss a McBSP word or something because of the > processor hiccup, and it's not actually an EDMA problem? Or maybe the processor > loses a state or EDMA misses an edge or something because of the brief stop. > > >Sounds like you've been at it a lot longer than I have ;-> > > Yeah I know you're smirking. But you'll get there. Some day you'll mention > "C6xx" and a young engineer working for you will say "yeah, I heard about that > one; it ran DOS, right?". > > >OK and yep - I have to receive data continuously and at quite a high rate. > > > >When you say you use "HPI" based tools - do you use them on the actual > >product (embedded) hardware or on development cards (such as the EVM). > > Both of course. > > Jeff Brower > DSP sw/hw engineer > Signalogic > > >BTW, this is so much better than TI Technical support !! I sent the same > >question to them about 4 weeks before I sent it to this group and I STILL > >haven't had anything more than their automated response. I think I'll be > >looking seriously at ADI DSPs next time .... > > Well keep that up and you'll get some help from TI, for sure ;-) > > But seriously, I have found that peer sources nearly always get a better result, > no matter the vendor.