Uhh, there are 1000 things which might be wrong. A bit like "my car is not working, it makes strange noise". Without having a look under the hood, there is just some wild guessing:
- Is your ROFS input at the right value? Your O-OFS?
- All VDD voltages there? Input voltage outside the rails?
- Your RSLOAD pulse long enough (>10ns)
- What happens if you put a really big sinal at the input, like 100 MHz sine wave with 2V p-p
The easiest is to have a look at the evaluation board and copy your new board like 1:1, also copy the VHDL readout code. Much easier that to start from scratch.
I am having a general problem getting read back using the ROI mode. In the transparent mode everything looks good. These are the steps that I take:
1) configure register (b"11111111",addr = "1100")
2) configure write shift register (b"11111111", addr = "1101")
3) assert DENABLE and DWRITE
4) wait for trigger
5) on trigger deassert DWRITE
6) Strobe RSRLOAD
7)Set drs4 address to enable all channels (address = "1001")
8)give n SRCLK pulses
9) goto 3 and repeat.
Am I missing something? Everything looks straight forward based on the manual yet in the readout mode I only get noise. I do get the stop position on SROUT and the refclk is at 475 KHz as desired and I get the desired behaviour for DTAP toggling at the same frequency as refclk.