Ethernet: Three-Speed Ethernet, MII Management
Table 34. MII Management AC Timing Specifications (continued)
At recommended operating conditions with LVDD is 3.3 V 10% or 2.5 V 5%.
Parameter/Condition
Symbol1
Min
Typ
Max
Unit
Notes
MDC fall time
Notes:
tMDHF
—
—
10
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, tMDKHDX symbolizes management data
timing (MD) for the time tMDC from clock reference (K) high (H) until data outputs (D) are invalid (X) or data hold time. Also,
tMDDVKH symbolizes management data timing (MD) with respect to the time data input signals (D) reach the valid state (V)
relative to the tMDC clock reference (K) going to the high (H) state or setup time. For rise and fall times, the latter convention
is used with the appropriate letter: R (rise) or F (fall).
2. This parameter is dependent on the csb_clk speed (that is, for a csb_clk of 267 MHz, the maximum frequency is 8.3 MHz
and the minimum frequency is 1.2 MHz; for a csb_clk of 375 MHz, the maximum frequency is 11.7 MHz and the minimum
frequency is 1.7 MHz).
3. This parameter is dependent on the csb_clk speed (that is, for a csb_clk of 267 MHz, the delay is 70 ns and for a csb_clk of
333 MHz, the delay is 58 ns).
Figure 17 shows the MII management AC timing diagram.
tMDCR
tMDC
MDC
tMDCF
tMDCH
MDIO
(Input)
tMDDVKH
tMDDXKH
MDIO
(Output)
tMDKHDX
Figure 17. MII Management Interface Timing Diagram
MPC8349EA PowerQUICC II Pro Integrated Host Processor Hardware Specifications, Rev. 13
Freescale Semiconductor
33
FREESCALE [ Freescale ]
