I'm trying to test using an external MCU to program the AD9164. I have an evaluation board for the chip, as well as an ADS7-V2. While using this set up, I want to test the FFH feature of the AD9164 by using an MCU to program the chip over SPI.
Looking at the spec sheet, it looks like the P2 connector on the AD9164-ebz board is for this purpose. However, none of the other peripherals (clock etc) are connected here, so presumably I'll need to program those over the USB connection, using the computer software ACE.
The specific question, then, is can I just plug my MCU pins into P2 to program the AD9164, without interfering with the USB programming of the other peripherals? I expect that if I avoid trying to do an SPI transfer via USB and the P2 connector at the same time then all will be fine, but I would like to be sure.
I should also point out that the application example in the AD9164 API documentation seems to imply that you can plug directly into the ADS7-V2 board and have it program the DAC chip over the FMC connector, but I can't find a suitable connector on the ADS7
For the purpose of just writing to AD9164, you can use P2 header. This just carry SPI signals: SDIO, SCLK, CS_b. The SDO signal is not routed. If you configure the AD9164 in 3-wire SPI mode, SDIO can be used for both read/write actions. As you've mentioned above, using P2 port, you just have access to AD9164. Remember that PIC controller is still SPI master and you can reach out to the clock chips via the USB connection on the board.
Another option would be to use FMC SPI pins. For this purpose FMC_SPI_EN pin must pulled low to take the SPI control out of PIC's hand. This SPI control can be done either by soldering wires to the FMC SPI pins (if the board is not plugged into the ADS7 board) or via the USB connection on the ADS7 board. However, the latter option is not released yet.
Thank you for the answer, I'll give it go via P2 to start.
Ok, so it looks like the PIC is active on the SPI pins after programming with ACE. For e.g. seems to be actively pulling the CS1 pin high. I guess that's what you mean when you say that the "PIC controller is still SPI master"
But then it seems to me that if we try to program the AD9164 via the P2 header in this case, we're likely going to damage the PIC (or our own MCU). I expect that if we don't use the USB connector at all, the PiC will not be active. But in this case we can't program the clock chips.
Do I understand correctly? I am a bit confused, as this does make it difficult to test the chip fully using the eval board.
If I am correct, then the only hope is to flip the FMC_SPI_EN pin, to disable the PIC when we write to P2 (or via the FMC pins). If so, is there any chance this functionality is available soon?