[U-Boot-Users] 440GX mfdcr/mtdcr

Kerl, John John.Kerl at Avnet.com
Wed Feb 18 00:21:52 CET 2004


Hello all,

I wonder if anyone has any advice on the following.  On our upcoming
440GX board (currently being fabbed), of course one of the first things
I will attempt to do, after a successful smoke test is to try to blink
some LEDs.  If I can do that, then probably my code path to the flash is
OK, etc.

Problem is:  GPIO0_OR, where I write my LEDs, is memory mapped, but the
pin control which allows one to specify that a given GPIO pin is marked
for output is a DCR.  The DCR for GPIO pin control, sdr0_pfc0, is DCR
0x4100.  mfdcr/mtdcr only allow a 10-bit operand.

Similarly affected are DCRs sdr0_cust0, sdr0_sdstp2, sdr0_cust1 and
sdr0_sdstp3, all above 0x4100.

Does anyone know how one could ever possibly read/write these high-numbered
DCRs?




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