BCM43907 Preliminary Data Sheet
Ethernet MAC (MII/RMII) Interface Timing
RMII Transmit Packet Timing
Figure 20 and Table 42 provide the RMII transmit packet timing.
Figure 20: RMII Transmit Packet Timing
REF_CLK
TX_EN
TXD[1]
TXD[0]
0
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
1
X
X
X
X
X
X
X
X
X
X
X
X
0
0
Preamble
SFD
Data
Table 42: RMII Transmit Packet Timing Parameters
Parameter
Symbol
Minimum Typical
Maximum Unit
REF_CLK Cycle Time
–
–
20
–
–
–
ns
ns
TXEN, TXER, TXD[1:0] setup time to
REF_CLK rising
TXEN_SETUP 4
TXEN, TXER, TXD[1:0] hold time from
REF_CLK rising
TXEN_HOLD
2
–
–
ns
Notes:
1. TXD[1:0] provides valid data for each REF_CLK period while TX_EN is asserted.
2. In 10 Mbps mode, there are ten REF_CLK periods per data period.
Broadcom®
March 12, 2016 • 43907-DS104-R
BROADCOM CONFIDENTIAL
Page 102
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