t2
PD<7:0>
t1
t5
t6
nACK
nALF
t4
t3
t4
FIGURE 24 - ECP PARALLEL PORT REVERSE TIMING
NAME
DESCRIPTION
PDATA Valid to nACK Asserted
nALF Asserted to PDATA Changed
nACK Asserted to nALF Deasserted
(Notes 1,2)
nACK Deasserted to nALF Asserted (Note 2)
nALF Asserted to nACK Asserted
nALF Deasserted to nACK Deasserted
MIN
0
0
TYP
MAX
UNITS
ns
ns
t1
t2
t3
80
200
200
ns
t4
t5
t6
80
0
0
ns
ns
ns
Note 1: Maximum value only applies if there is room in the FIFO and terminal count has not been received. ECP can
stall by keeping nALF low.
Note 2: nACK is not considered asserted or deasserted until it is stable for a minimum of 75 to 130 ns.
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