Rocket I/O receiver

[Matthias Müller]

Hello,
I want to receive a seriell datastream at 20 x 142MHz = 2,84Gb/s with a
Rocket I/O cell. Do I need to connect the external BREFCLK (142MHz) to
RECEIVE data with a Rocket I/O cell or can I use the recovered clock
RXRECCLK in the design?
Thank you for answers,
Matthias

 

[Austin Lesea]

Matthias,

If you want to have your received data aligned with the right clock, you
use the received recovered clock (RXRECCLK).

If the transmit clock source is the same as the receive clock source
(say the 142 MHz is distributed to all cards on a backplane) then you
can use the FIFO in the receiver to align the phase to the master clock
source (RXRECCLK clock into FIFO, master OSC clock out of FIFO).

If different transmit clock frequency is used, then the FIFO will
overflow or underflow, and you should not be using the master clock for
receive timing (as it is different from he transmit).

Austin

Matthias Müller wrote:

Hello,
I want to receive a seriell datastream at 20 x 142MHz = 2,84Gb/s with a
Rocket I/O cell. Do I need to connect the external BREFCLK (142MHz) to
RECEIVE data with a Rocket I/O cell or can I use the recovered clock
RXRECCLK in the design?
Thank you for answers,
Matthias