PCM18XK1 Microchip Technology, PCM18XK1 Datasheet - Page 167

• Manufacturer Part Number: PCM18XK1
• Description: MODULE PROC PIC18F8680,6680,8565
• Manufacturer: Microchip Technology

Specifications of PCM18XK1

• Accessory Type: Processor Module
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: ICE2000
• For Use With: ICE2000 - EMULATOR MPLAB-ICE 2000 POD
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

14.1
Timer3 can operate in one of these modes:
• As a timer
• As a synchronous counter
• As an asynchronous counter
The operating mode is determined by the clock select
bit, TMR3CS (T3CON<1>).
FIGURE 14-1:
FIGURE 14-2:
 2004 Microchip Technology Inc.
Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
Set TMR3IF Flag bit
on Overflow
Note 1: When the T1OSCEN bit is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
T1OSO/
T13CKI
T1OSI
Timer3 Operation
Data Bus<7:0>
Write TMR3L
Read TMR3L
TMR3IF
Overflow
Interrupt
Flag bit
T1OSO/
T13CKI
T1OSI
T1OSC
TIMER3 BLOCK DIAGRAM
TIMER3 BLOCK DIAGRAM CONFIGURED IN 16-BIT READ/WRITE MODE
8
TMR3H
High Byte
TMR3H
T1OSC
Timer3
8
To Timer1 Clock Input
Enable
Oscillator
T1OSCEN
8
TMR3
TMR3L
Oscillator
(1)
Enable
T1OSCEN
8
PIC18F6585/8585/6680/8680
TMR3L
CLR
(1)
(3)
Clock
CLR
Internal
F
OSC
/4
TMR3ON
F
Internal
Clock
On/Off
OSC
TMR3CS
When TMR3CS = 0, Timer3 increments every instruc-
tion cycle. When TMR3CS = 1, Timer3 increments on
every rising edge of the Timer1 external clock input or
the Timer1 oscillator if enabled.
When the Timer1 oscillator is enabled (T1OSCEN is
set), the RC1/T1OSI and RC0/T1OSO/T13CKI pins
become inputs. That is, the TRISC<1:0> value is
ignored and the pins are read as ‘0’.
Timer3 also has an internal “Reset input”. This Reset
can be generated by the CCP module (Section 14.0
“Timer3 Module”).
CCP Special Trigger
T3CCPx
/4
1
0
TMR3ON
On/Off
TMR3CS
T3CKPS1:T3CKPS0
1
0
T3CCPx
T3SYNC
CCP Special Trigger
Prescaler
1, 2, 4, 8
T3CKPS1:T3CKPS0
0
1
T3SYNC
2
Prescaler
1, 2, 4, 8
0
1
2
Synchronized
Clock Input
Synchronize
Sleep Input
Synchronized
det
Clock Input
Synchronize
Sleep Input
DS30491C-page 165
det