Intel 80C186XL User Manual page 234

Counter =
Compare "A"
?
No
Pulse TOUT Pin
Low For 1 Clock
Yes
Continuous Mode
(CONT=1)
?
No
Clear Enable Bit
(Stop Counting)
Figure 9-3. Timers 0 and 1 Flow Chart (Continued)
Continued From
"A"
Alternating
No
Maxcount Regs
(ALT = 1)
?
Yes
Yes
(Use"A")
No
Counter =
Compare "A"
Done
Set RIU Bit
TOUT Pin Driven Low
No
Interrupt Bit Set
Request Interrupt
Clear Counter
Done
TIMER/COUNTER UNIT
Yes
Using
Maxcount A
(RIU = 0)
?
?
Yes
TOUT Pin Driven High
Yes
Continuous Mode
?
Yes
No
(Use"B")
No
Counter =
Compare "B"
?
Yes
Clear RIU Bit
(CONT=1)
?
No
Clear Enable Bit
(Stop Counting)
A1295-0A
9-5