Counter/Timers (8254)
Table 11-1
Read-Back Command Example.
COMMAND
D7 D6 D5 D4 D3 D2 D1 D0
DESCRIPTION
RESULTS
1
1
0
0
0
0
1
0
Read back count and
Count and status
status of counter 0
latched for counter 0
1
1
1
0
0
1
0
0
Read back status of
Status latched for
counter 1
counter 1
1
1
1
0
1
1
0
0
Read back status of
Status latched for
counters 2,1
counter 2 but not
counter 1
1
1
0
1
1
0
0
0
Read back count of
Count latched for
counter 2
counter 2
1
1
0
0
0
1
0
0
Read back count and
Count latched for
status of counter 1
counter 1, but not
status
1
1
1
0
0
0
1
0
Read back status
Command ignored,
of counter 1
status already latched
for counter 1
11-15
