Texas Instruments THUNDERSWITCH II TNETX4090 - Manual (Page 66)

TNETX4090
ThunderSWITCH II

9-PORT 100-/1000-MBIT/S ETHERNET

SWITCH
SPWS044E – DECEMBER 1997 – REVISED AUGUST 1999
66
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
MII (ports 0–8)
Figures 21–23 show the timing for the eight MIIs operating at either 10-Mbit/s or 100-Mbit/s, and the GMII
operating at 100-Mbit/s.
Mxx_CRS and Mxx_COL are driven asynchronously by the PHY. Mxx_RXD3–Mxx_RXD0 is driven by the PHY
on the falling edge of Mxx_RCLK. Mxx_RXD3–Mxx_RXD0 timing must be met during clock periods in which
Mxx_RXDV is asserted. Mxx_RXDV is asserted and deasserted by the PHY on the falling edge of Mxx_RCLK.
Mxx_RXER is driven by the PHY on the falling edge of Mxx_RCLK.
MII receive (see Figure 21)
NO. MIN MAX UNIT
1 tsu(Mxx_RXD) Setup time, Mxx_RXD3–Mxx_RXD0 valid before Mxx_RCLK ↑ 8 ns
1 tsu(Mxx_RXDV) Setup time, Mxx_RXDV valid before Mxx_RCLK
↑
8 ns
1 tsu(Mxx_RXER) Setup time, Mxx_RXER valid before Mxx_RCLK
↑
8 ns
2 th(Mxx_RXD) Hold time, Mxx_RXD3–Mxx_RXD0 valid after Mxx_RCLK
↑
8 ns
2 th(Mxx_RXDV) Hold time, Mxx_RXDV valid after Mxx_RCLK
↑
8 ns
2 th(Mxx_RXER) Hold time, Mxx_RXER valid after Mxx_RCLK
↑
8 ns
ОООООО
ОООООО
ОООООО
ОООООО
ОООООО
ОООООО
Mxx_RXD3–Mxx_RXD0
Mxx_RXDV
Mxx_RXER
1 2
Mxx_RCLK
Figure 21. MII Receive
NOTE: For port 8, M08_RFCLK is used for the transmit clock input.
Mxx_CRS and Mxx_COL are driven asynchronously by the PHY. Mxx_TXD3–Mxx_TXD0 is driven by the
reconciliation sublayer synchronous to Mxx_TCLK. Mxx_TXEN is asserted and deasserted by the reconciliation
sublayer synchronous to the Mxx_TCLK rising edge. Mxx_TXER is driven synchronous to the rising edge of
Mxx_TCLK.