timing for the dynamic driver change
specified in then IEEE 1284 Extended
is
Interface Standard, Rev. 1.14, July 14, 1993,
available from Microsoft. The dynamic driver
change must be implemented properly to
prevent glitching the outputs.
Capabilities Port
Protocol
and ISA
t6
t3
PDATA
t1
t2
t5
nSTROBE
t4
BUSY
FIGURE 16 - PARALLEL PORT FIFO TIMING
NAME
DESCRIPTION
MIN
600
600
450
TYP
MAX
UNITS
ns
t1
t2
t3
t4
t5
t6
DATA Valid to nSTROBE Active
nSTROBE Active Pulse Width
ns
DATA Hold from nSTROBE Inactive (Note 1)
nSTROBE Active to BUSY Active
BUSY Inactive to nSTROBE Active
BUSY Inactive to PDATA Invalid (Note 1)
ns
500
ns
680
80
ns
ns
Note 1: The data is held until BUSY goes inactive or for time t3, whichever is longer. This only
applies if another data transfer is pending. If no other data transfer is pending, the data is
held indefinitely.
172
SMSC [ SMSC CORPORATION ]
