Intel 386

10-9
TIMER/COUNTER UNIT
Figure 10-5. Mode 1 – Basic Operation
Figure 10-6 shows retriggering the one-shot. On the CLKINn pulse following the retrigger, the
counter reloads the count. The control logic then decrements the count on each succeeding
CLKINn pulse; OUTn remains low until the count reaches zero.
Figure 10-6. Mode 1 – Retriggering the One-shot
Writes to
Counter
n
CLKIN n
GATE n
OUT n
?????
0003
0002 0001 0000 FFFF 0003
Control
Word = 12H
Count
0002
Count = 3
A2312-02
Writes to
Counter
n
CLKIN n
GATE n
OUT n
?????0003 0002 0001 0003 0002 0001
Control
Word = 12H
Count
0000
Count = 3
A2396-01