Mode 3 – Writing A New Count (Without A Trigger) - Intel 386 User Manual

Figure 10-14 and Figure 10-15 shows writing a new count. If the counter receives a gate-trigger
after writing a new count but before the end of the current half-cycle, the count is loaded on the
next CLKINn pulse and counting continues from the new count (Figure 10-14). Otherwise, the
new count is loaded at the end of the current half-cycle (Figure 10-15).
Control
Word = 16H
Writes to
Counter n
CLKIN n
GATE n
OUT n
?
Count
Figure 10-14. Mode 3 – Writing a New Count (With a Trigger)
Control
Word = 16H
Writes to
Counter n
CLKIN n
GATE n
OUT n
? ?
Count
Figure 10-15. Mode 3 – Writing a New Count (Without a Trigger)
Count = 8
? ? ? 8 6
Count = 4
? ? 4 2
Count = 10
4 2 8 6 4
Count = 8
4 2 4 2 8
TIMER/COUNTER UNIT
10 8 6
A2407-02
6 4 2
A2406-01
10-15