Thanks for replying Stefan.
I was more so just concerned with the steps in the firmware when I had asked. However, yes the ROFS (1.05V) and O-OFS (0.9 V was 1.3 V earlier but, changed this becasue of ADC input requirements) are per spec, the VDD voltages are all there and input voltages are within the rails and finally the RSLOAD (16 ns) too is ok. Looking at your eval board firmware , on appearance it looks exactly like what I am doing. I thought maybe I was/ still am missing some intermediate addressing stage. What I wrote earlier is what I still have.
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.