DAC34H84: DAC34H84 NCO SYNC

New2day,

We are looking into this.

Regards,

Jim

We are stuck.

Any updates? Thanks! 

Hi Jim and or everyone from TI support, 

Here are some info and questions  from our side,

Info, 

- our NCO is set to 20MHz or 25MHz with both DACCLK and Data CLK at 250MHz; 

- our OSTR is 15.625MHz and ISTR is a pulse wihtout DAC internal PLL;

- out input FIFO and NCO use ISTR; output FIFO and CLKDIV use OSTR;

- we are able to get base band and raw data (no NCO) aligned after many many tests (way to many)

- the outputs became out off SYNC whenever enabling the NCO, most of time almost 180 degree offset

Questions

1. in case ISTR for input FIFO and OSTR for output FIFO, would SYNC signal have to be used for synchronizing NCO? 

2. should the config45 bit[14] be set if OSTR was used for CLKDIV? 

3. how the ISTR, SYNC and OSTR should be toggled if they are used for input FIFO, NCO and output FIFO respectively.

4. which source should be used for NCO and QMC if ISTR for input FIFO and OSTR for output FIFO and CLKDIV?

5. Was there set-up sequence available for SYNC multi-devices? 

6. How did you test the multi-device synchronization. Just follow exact what in the datasheet, table 10???

7. Can sif_sync be used to synchronize NCO or so from multi-devices? If yes, was it bullet proved? 

8. If NCO QMC is using SYNC while ISTR and OSTR for FIFOs, should SYNC be toggled before or after FIFO alarms cleared? How many times should it be toggled? 

9. Would all SYNC-source be guarantee multi-device  synchronization? And any combinations, orders and times of toggling if not periodical signals?

Hope to hear from you ASAP!!! Thanks.

New2day,

We are looking into this issue. Is this on a TI EVM or a custom board?

Regards,

Jim