Intel 386 - Manual (Page 258)

10-15
TIMER/COUNTER UNIT
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).
Figure 10-14. Mode 3 – Writing a New Count (With a Trigger)
Figure 10-15. Mode 3 – Writing a New Count (Without a Trigger)
? ? ? ? 8 6 4 2 8 6 4 10
Writes to
Counter n
CLKIN n
GATE n
OUT n
Control
Word = 16H
Count 8 6
Count = 8 Count = 10
A2407-02
A2406-01
? ? ? ? 4 2 4 2 4 2 8 6
Writes to
Counter n
CLKIN n
GATE n
OUT n
Control
Word = 16H
Count 4 2
Count = 4 Count = 8