CRC is an optional interface. The crc_valid and crc_pass_fail_n signals
(see the following table) indicate the result of a received frame transmitted with
CRC. See Using CRC for more information.
| Name | Direction | Clock Domain | Description |
|---|---|---|---|
| CORE_STATUS | |||
| crc_valid | Output | user_clk | Samples the crc_pass_fail_n signal. |
| crc_pass_fail_n | Output | user_clk | The crc_pass_fail_n signal is asserted as High when the received CRC matches the transmitted CRC. This signal is not asserted if the received CRC is not equal to the transmitted CRC. The crc_pass_fail_n signal should always be sampled with the crc_valid signal. |
The following figure illustrates checking CRC at the core level. The
figure shows 6 n bytes of received data of a frame. At the end of the frame, the
core asserts m_axi_rx_tlast and crc_valid. In the same clock cycle, the transmitted and
computed CRCs are compared. If the values match, the crc_pass_fail_n signal is asserted.
Figure 1. A 6n Data Beats Frame
with CRC
