IXF1104 4-Port Gigabit Ethernet Media Access Controller
Datasheet 141
Document Number: 278757
Revision Number: 007
Revision Date: March 25, 2004
7.4 GMII AC Timing Specification
7.4.1 1000 Base-T Operation
Figure 38 and Figure 39 and Table 49 and Table 50 provide GMII AC timing specifications.
7.4.1.1 1000 BASE-T Transmit Interface
Figure 38. 1000BASE-T Transmit Interface Timing
Table 49. GMII 1000BASE-T Transmit Signal Parameters
Symbol Parameter Min Typ
1
Max Unit
2
t1 TXD[7:0], TXEN, TXER Set-up to TXC High 2.5 – – ns
t2 TXD[7:0], TXEN, TXER Hold from TXC High 0.5 – – ns
t3 TXEN sampled to CRS asserted – – 16 BT
t4 TXEN sampled to CRS de-asserted – – 16 BT
1. Typical values are at 25
o
C and are for design aid only; not guaranteed and not subject to production
testing.
2. Bit Time (BT) is the duration of one bit as transferred to/from the PHY and is the reciprocal of bit rate. BT for
1000BASE-T = 10
-9
or 1 ns.
B0634-01
GTX_CLK
TXEn
TXD[7:0]
TXER
CPS
t1
t3
t4
t2