Hi, Analog Team!
We have designed a customized board with AD9695(3Nos) & HMC7044 and are facing problems while trying to perform multichip NCO synchronization.
First of all, It would be greatly helpful if you could clarify some of the below doubts,
1)while trying to follow Figure 133. SYSREF± Capture Scenarios and Multichip Synchronization, we are un-able to find the “JESD204B LMFC Alignment Required?” Control Register. Can you please specify the register used for the marked function as shown below,
2)we tried to perform NCO Multichip Synchronization mentioned in Page52 of data sheet and configured
0x0040-> 31 & 0x0041->80 (Chip FD_B/GPIO_B0 set as MNTO) in ADC1
0x0040-> 31 & 0x0041->90 (Chip FD_B/GPIO_B0 set as SNTI). In ADC2.
As all GPIO are connected to FPGA in our module, we planned to relay the MNTO Signal From ADC1 to SNTI of ADC2, But observed that the MNTO never Went High. Is there something we missed out for using Master/Slave Synchronization Triggering mechanism?
3)In NCO Multi chip synchronization Figure 104, It is shown that a common signal is routed to all ADC, Can you please share the Function/pin details for this signal?
We are operating in subclass1, Sysref continuous mode, we are able to perform multi NCO synchronization by writing NCO synchronization bit (300 → 3) in all ADC's. And phase matching works fine. But due to continuous sysref, we are observing sysref spurs in ADC output at ~ -49dBc, which is un-suitable for our application. Hence we opted for N-shot mode. And are observing the following issues,
we configured HMC7044 in pulse generator mode(8pulses) & kept sysref channels in dynamic mode and AD9695 in subclass1(0x0590 → 2F), N-shot(0x0120 → 4) and NCO next sysref sync(0x0300 → 3). we then perform Jesd Lane bonding by asserting sync and ILA sequence gets completed & we are able to log data. At this instance, verified that the ADC's are waiting for Sysref Pulses(read 0x0120 → 4). we then give pulse generator request to HMC7044, and then read 0x0120 → 0 & 0x0300 → 2 which indicates sysref is received, but observed ADC channel bonding gets disrupted. Why ? Is there any sequence to achieve synchronization with N-shot mode.
We also observed that, on providing Sysref Pulse(8), in ADC2 Both Sysref N-shot(0x0120) + NCO sync(0x0300) gets cleared while in ADC & ADC3, only Sysref N-shot(0x0120) is getting cleared. Is there any timing that needs to be met for performing both with a single Pulse request?
Kindly guide us achieve Multi Chip NCO synchronization with AD9695 in N-shot mode.
Thanks in advance,