Other Parts Discussed in Thread: LMK04828,
I am trying to configure the LMK04828 on a DAC38j82EVM board for 4-wire mode to be used with the FMC connector.
I have set bit 4 on register 0x000 to 1 to disable 3-wire mode. I have also configured register 0x14a to 0x33 (push-pull output for RESET as SPI readback).
However, I still can't get it to work. I can access and configure the DAC without issue. Looking at the CPLD code I noticed this part of the code related to SDO:
...
// Control routing of LMK and DAC SDO to FTDI or FMC
reg SDO_ROUTE;
always @ (*) begin
if(!FTDI_SEN_LMK && FTDI_SEN_DAC) begin
SDO_ROUTE <= LMK_SDO;
end else begin
SDO_ROUTE <= DAC_SDO;
end
end
assign FTDI_SDO = (!FMC_OR_FTDI_SELECTOR) ? SDO_ROUTE : 1'bz;
assign FMC_SDO = (FMC_OR_FTDI_SELECTOR) ? SDO_ROUTE : 1'bz;
It seems LMK_SDO is only routed as SDO_ROUTE when the FTDI signals are set to select the LMK but it defaults to DAC_SDO for other cases which would include the case where we are using FMC_SEN_* instead.
Can someone confirm this? What would be the easiest way to update the CPLD's firmware?
Thanks beforehand,
Juan
