PIC18FXX39 Datasheet, PDF (110/322 Pages) Microchip Technology – Enhanced FLASH Microcontrollers with Single Phase Induction Motor Control Kernel

PIC18FXX39
13.1 Timer3 Operation
Timer3 can operate in one of these modes:
• As a timer
• As a synchronous counter
• As an asynchronous counter
FIGURE 13-1:
TIMER3 BLOCK DIAGRAM
TMR3IF
Overflow
Interrupt
Flag bit
TMR3H TMR3L
The Operating mode is determined by the clock select
bit, TMR3CS (T3CON<1>). When TMR3CS = 0,
Timer3 increments every instruction cycle. When
TMR3CS = 1, Timer3 increments on every rising edge
of the Timer1 external clock input.
0
TMR3ON
On/Off
1
T3SYNC
Synchronized
Clock Input
T13CKI
1
FOSC/4
Internal
Clock
0
TMR3CS
Prescaler
1, 2, 4, 8
2
T3CKPS1:T3CKPS0
Synchronize
det
SLEEP Input
FIGURE 13-2:
TIMER3 BLOCK DIAGRAM CONFIGURED IN 16-BIT READ/WRITE MODE
Data Bus<7:0>
8
TMR3H
8
8
Write TMR3L
Read TMR3L
Set TMR3IF Flag bit
on Overflow
8
TMR3
Timer3
High Byte
TMR3L
T13CKI
To Timer1 Clock Input
0
Synchronized
Clock Input
TMR3ON
On/Off
1
T3SYNC
1
FOSC/4
Internal 0
Clock
Prescaler
1, 2, 4, 8
2
T3CKPS1:T3CKPS0
TMR3CS
Synchronize
det
SLEEP Input
DS30485B-page 110
Preliminary
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