RE: [ethmac] mii rx hold time

["Igor Mohor" <igorm@opencores.org>]

No, tx_clk and rx_clk are not synchronous. PHY generates both signals. Yes, the hold time will meet. tx_clk and rx_clk

are 25 Mhz (40 ns).

 

Regards,

    Igor

 

 

-----Original Message-----
From: owner-ethmac@opencores.org [mailto:owner-ethmac@opencores.org]On Behalf Of zou.yixin@zte.com.cn
Sent: 24. december 2001 9:38
To: ethmac@opencores.org
Subject: [ethmac] mii rx hold time

hi,
Merry Christmas!

The following  is quoted from 802.3-2000E.
"Figure 22¨C15 shows the timing relationship for the signals associated with the receive data path at the MII
connector. The timing is referenced to the rising edge of the RX_CLK. The input setup time shall be a minimum
of 10 ns and the input hold time shall be a minimum of 10 ns."

"Figure 22¨C14 shows the timing relationship for the signals associated with the transmit data path at the MII
connector. The clock to output delay shall be a minimum of 0 ns and a maximum of 25 ns."

When i send data synchronouly with respect to TX_CLK rising edge,can the 10ns hold time met ?I assume the tx_clk and rx_clk are synchronous(right?). How to avoid the hold time violation.

  Thanks.

                            yxzhou.