Lpc2000

Hello everyone,

We (I and my colleague) have been battling with the SSP bus on an
LPC2138, so far unsuccessfully. Whatever we try, the registers always
return 0.

Two examples:

1. The SSPSR register is always zero. This is a read-only status
register with a non-zero reset value. If we read the manual correctly,
at least either the BSY (busy) or the TFE (transmit FIFO empty) bits
must be set. This register should therefore never be 0.

2. The SSPCPSR is always reads back zero, even though we set it to a
different value just prior to reading it back. The SSPCPSR is the
clock pre-scale register; it can hold an even value (between 2 and
254) and is read/write.

All other registers also read back 0. And, by the way, we measure
nothing on the output pins. The SPP port is powered up (PCOMP), the
PINSEL registers are correct, and we have the correct register
addresses for the SPP peripheral: 0xE0068000 - 0xE0068020.

Any idea what's going on?

Thanks in advance for any help,
Thiadmer