COM20020-5 Datasheet, PDF (53/58 Pages) SMSC Corporation – Universal Local Area Network Controller with 2K x 8 On-Board RAM

nTXEN
t1
nPULSE1
nPULSE2
(Internal Clk)
t9
t4
t3
t2
t5
t6
t7
t8
LAST BIT
(200 nS BIT TIME)
t10
RXIN
t11
Parameter
min typ max
t1 _{nPULSE2 High to nTXEN Low}
t2 _{nPULSE1 Pulse Width}
t3 _{nPULSE1 Period}
t4 _{nPULSE2 Low to nPULSE1 Low}
t5 _{nPULSE2 High Time}
t6 _{nPULSE2 Low Time}
t7 nPULSE2 Period
t8 nPULSE2 High to nTXEN High
0
25
100*
200*
0
25
50*
50*
100*
0
25
(First rising edge on nPULSE2 after Last Bit Time)
t9 _{nTXEN Low to first nPULSE1 Low**}
300
400
t10 _{RXIN Pulse Width}
t11 _{RXIN Period}
10 100*
200*
* t5,t6 = 2 x (crystal period) for clock frequencies other than 40 MHz.
* t2,t7,t10 = 4 x (crystal period) for clock frequencies other than 40 MHz.
* t3,t11 = 8 x (crystal period) for clock frequencies other than 40 MHz.
This period applies to data of two consecutive one's.
** t9: For clock frequencies other than 40 MHz, t9 = 14 x (clock period) ± 50 nsec.
units
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
FIGURE 15 - BACKPLANE MODE TRANSMIT OR RECEIVE TIMING
(These signals are to and from the differential driver or the cable)
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