Ethernet: Three-Speed Ethernet, MII Management
Table 26. GMII Receive AC Timing Specifications (continued)
At recommended operating conditions with LVDD/OVDD of 3.3 V 10%.
Parameter/Condition
Symbol1
Min
Typ
Max
Unit
RX_CLK clock rise (20%–80%)
RX_CLK clock fall time (80%–20%)
Note:
tGRXR
tGRXF
—
—
—
—
1.0
1.0
ns
ns
1. The symbols for timing specifications follow the pattern of t(first two letters of functional block)(signal)(state)(reference)(state) for inputs
and t(first two letters of functional block)(reference)(state)(signal)(state) for outputs. For example, tGRDVKH symbolizes GMII receive timing
(GR) with respect to the time data input signals (D) reaching the valid state (V) relative to the tRX clock reference (K) going
to the high state (H) or setup time. Also, tGRDXKL symbolizes GMII receive timing (GR) with respect to the time data input
signals (D) went invalid (X) relative to the tGRX clock reference (K) going to the low (L) state or hold time. In general, the clock
reference symbol is based on three letters representing the clock of a particular function. For example, the subscript of tGRX
represents the GMII (G) receive (RX) clock. For rise and fall times, the latter convention is used with the appropriate letter:
R (rise) or F (fall).
Figure 10 shows the GMII receive AC timing diagram.
G
tGRX
tGRXR
RX_CLK
tGRXF
tGRXH
RXD[7:0]
RX_DV
RX_ER
tGRDXKH
tGRDVKH
Figure 10. GMII Receive AC Timing Diagram
8.2.2
MII AC Timing Specifications
This section describes the MII transmit and receive AC timing specifications.
8.2.2.1
MII Transmit AC Timing Specifications
Table 27 provides the MII transmit AC timing specifications.
Table 27. MII Transmit AC Timing Specifications
At recommended operating conditions with LVDD/OVDD of 3.3 V 10%.
Parameter/Condition
Symbol1
Min
Typ
Max
Unit
TX_CLK clock period 10 Mbps
TX_CLK clock period 100 Mbps
TX_CLK duty cycle
tMTX
tMTX
tMTXH/ MTX
tMTKHDX
—
—
35
1
400
40
—
5
—
—
65
15
ns
ns
%
t
TX_CLK to MII data TXD[3:0], TX_ER, TX_EN delay
ns
MPC8347EA PowerQUICC II Pro Integrated Host Processor Hardware Specifications, Rev. 12
Freescale Semiconductor
26
FREESCALE [ Freescale ]
