LAN8740A Datasheet, PDF (123/136 Pages) Microchip Technology – Small Footprint MII/RMII 10/100 Energy Efficient Ethernet Transceiver with HP Auto-MDIX and flexPWR® Technology

LAN8740A/LAN8740Ai
5.6.4.1 RMII CLKIN Requirements
TABLE 5-13: RMII CLKIN (REF_CLK) TIMING VALUES
Parameter
CLKIN frequency
CLKIN Frequency Drift
CLKIN Duty Cycle
CLKIN Jitter
Min. Typ. Max.
50
±50
40
60
150
Unit
MHz
ppm
%
ps
Note
p-p – not RMS
5.6.5 SMI TIMING
This section specifies the SMI timing of the device. Please refer to Section 3.5, "Serial Management Interface (SMI)" for
additional details.
FIGURE 5-7:
SMI TIMING
MDC
(INPUT)
t_val
t_oinvld
MDIO
(Data-Out)
t_clkp
t_clkh t_clkl
t_oinvld
t_su t_ihold
MDIO
(Data-In)
TABLE 5-14: SMI TIMING VALUES
Symbol
Description
Min.
Max.
Unit
t_clkp
MDC period
400
ns
t_clkh
MDC high time
160 (80%)
ns
t_clkl
MDC low time
160 (80%)
ns
t_val
MDIO (read from PHY) output valid from rising edge of MDC
300
ns
t_oinvld
MDIO (read from PHY) output invalid from rising edge of MDC
0
ns
t_su
MDIO (write to PHY) setup time to rising edge of MDC
10
ns
t_ihold
MDIO (write to PHY) input hold time after rising edge of MDC
10
ns
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DS00001987A-page 123