Is it possible to configure the Tx and Rx with different data rates?
The Rx data rate can be either 2 times the Tx data rate or equal to the Tx data rate. These are the only 2 options.
Did you get around to using the device in the 2x fashion?
I've found the configuration bits that allow me to specify the Tx DAC_CLK to be either 1/2 or equal to the Rx ADC_CLK, so I guess the data rate into / out of the DAC and ADC can be different, but is it possible to have different data rates on the digital interface to the BBP? Or if the device is used in DAC_CLK = ADC_CLK/2 mode does one need to specify different Interpolation / Decimation rates so that the data rates on the digital interface are identical?
For my application I'd like to run the BB Tx at symbol rate, but use 4 x oversampling for the Rx. So there is a mismatch of 4 x. I can't see any examples of running the digital interface with different data rates for Rx and Tx.
There are two allowed cases: (1) Rx sample rate = Tx sample rate and (2) Rx sample rate = 2*Tx sample rate. In both cases, however, FB_CLK must be equal to DATA_CLK.
Thanks tlili, as in most cases an answer to a technical question begets a more questions....
OK, I've found D7 of SPI Register 0x012 - Parallel Port Configuration 3, "When set, the Rx rate is twice the Tx rate". You state that "FB_CLK must be equal to DATA_CLK", and I've seen that indicated elsewhere, in fact FB_CLK should be a fed back version of DATA_CLK.
Are there any timing diagrams available that shows how the digital interface works in Rx Sample Rate = 2*Tx Sample Rate mode? Is it true to say that TX_FRAME rate = 0.5 * RX_FRAME rate in this mode? All of the timing diagrams that I've seen for FDD have shown both TX_FRAME and RX_FRAME as the same rate and 50% duty cycle. I'm expecting to be using 1R1T FDD on a Dual Port Full Duplex Mode, I'm undecided about using DDR or SDR.
FDD Rx Rate = 2 x Tx Rate is only available in FDD mode. We do not have a timing diagram for this mode.
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