SMSC LAN8720i User Manual
Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
Revision 1.0 (05-28-09)
56
SMSC LAN8720/LAN8720i
DATASHEET
6.2
RMII 10/100Base-TX/RX Timings (50MHz REF_CLK IN)
The 50MHz REF_CLK IN timing applies to the case when nINTSEL is floated or pulled-high on the
LAN8720. In this mode, a 50MHz clock must be provided to the LAN8720 CLKIN pin. For more
information on REF_CLK IN Mode, see
LAN8720. In this mode, a 50MHz clock must be provided to the LAN8720 CLKIN pin. For more
information on REF_CLK IN Mode, see
.
6.2.1
RMII 100Base-T TX/RX Timings (50MHz REF_CLK IN)
6.2.1.1
100M RMII Receive Timing (50MHz REF_CLK IN)
Figure 6.2 100M RMII Receive Timing Diagram (50MHz REF_CLK IN)
Table 6.2 100M RMII Receive Timing Values (50MHz REF_CLK IN)
PARAMETER
DESCRIPTION
MIN
TYP
MAX
UNITS
NOTES
T6.1
Output delay from rising edge of
CLKIN to receive signals output
valid
CLKIN to receive signals output
valid
3
10
ns
CLKIN frequency
50
MHz
Clock In -
CLKIN
Data Out -
RXD[1:0]
CRS_DV
Valid Data
T
6.1