Re: [Xc3sprog-users] XCFP does not yet support bitfile subranges

[Joris v. R. <jor...@jo...>]

Hi Mirko,

On 2012-02-20, Mirko Ciecinski wrote:
> Programming with your patched xc3sprog consumes 10 times longer than
> with patched V0.5-version (327 sec <-> 31 sec).

Yes, programming time is a problem with this code. Especially
DLC10-type cables seem to be very slow when alternating between short
writes and status polling.

I'm following the programming flow from the Xilinx BSDL file. Your
special code uses a different trick to handle the timing of the
programming process. It may work only with certain types of cables or
certain bitrate configurations of the cable.

> As you mentioned,
> maybe CCB=0xffff is not the fastest setting.

I did not mention that. The setting of CCB has nothing to do with
programming speed.

> But I cannot figure out
> the differences in progalgxcfxxp.cpp. I find only CCB[2] ..., see
> below:

This is where XC3SPROG sets the CCB register. Currently the contents is
fixed at 0xffff, as you can see:

    data[0] = 0xff;
    data[1] = 0xff;
    jtag->shiftIR(XSC_DATA_CCB);
    jtag->shiftDR(data, 0, 16);

> Are you going to add XCFP-specific command-line option for the CCB
> register?

Probably not soon. I currently don't have an XCFP board available, and
I don't want to mess around with code that I can't test properly.

Joris.