Tnetx4090 thunderswitch ii, Switch – Texas Instruments THUNDERSWITCH II TNETX4090 User Manual
Page 62
TNETX4090
ThunderSWITCH II
9-PORT 100-/1000-MBIT/S ETHERNET
SWITCH
SPWS044E – DECEMBER 1997 – REVISED AUGUST 1999
62
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
physical medium attachment interface (port 8)
receive
PMA receive (see Figure 16)
NO.
MIN
MAX
UNIT
1
tc(Mxx_RBC)
Cycle time, receive byte clock 0 and 1 (Mxx_RCLK, Mxx_COL)
16
16
ns
–
tdrift(Mxx_RBC)
Drift rate† of receive bye clock 0 and 1
0.2
ns
2,3
tw(Mxx_RBC)
Pulse duration, Mxx_RCLK, Mxx_COL low or high
40%
60%
ns
4
tsu(Mxx_RXD)
Setup time, Mxx_RXD7–Mxx_RXD0 valid before Mxx_RCLK/COL
↑
2.5
ns
4
tsu(Mxx_RXDV)
Setup time, Mxx_RXDV valid before Mxx_RCLK/COL
↑
2.5
ns
4
tsu(Mxx_RXER)
Setup time, Mxx_RXER valid before Mxx_RCLK/COL
↑
2.5
ns
5
th(Mxx_RXD)
Hold time, Mxx_RXD7–Mxx_RXD0 valid after Mxx_RCLK/COL
↑
1.5
ns
5
th(Mxx_RXDV)
Hold time, Mxx_RXDV valid after Mxx_RCLK/COL
↑
1.5
ns
5
th(Mxx_RXER)
Hold time, Mxx_RXER valid after Mxx_RCLK/COL
↑
1.5
ns
6
tskew(Mxx_RBC)
Skew between receive byte clock 1 and receive byte clock 0
7.5
8.5
ns
† tdrift is the (minimum) time for either RBC0 or RBC1 to drift from 63.5 MHz to 64.5 MHz or 60 Mhz to 59 MHz from their lock value. It is applicable
under all input signal conditions (except under certain circumstances during comma detection), including invalid or absent input signals, if the
receiver clock recovery unit was previously locked to Mxx_RFCLK or to a valid input signal.
ОО
ОО
ООООООО
ММММММММММММ
ММММММММММММ
ООООООООООО
Receive Byte
Clock 0
Data Group
1
6
2
5
4
4
5
Comma Detect
Receive
Code Group
Receive Byte
Clock 0
3
Figure 16. PMA Receive