PIC18F23K20-E/MLQTP MICROCHIP [Microchip Technology], PIC18F23K20-E/MLQTP Datasheet - Page 144

• Manufacturer Part Number: PIC18F23K20-E/MLQTP
• Description: 28/40/44-Pin Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F2XK20/4XK20
12.1
Timer1 can operate in one of the following modes:
• Timer
• Synchronous Counter
• Asynchronous Counter
The operating mode is determined by the clock select
bit, TMR1CS of the T1CON register. When TMR1CS is
cleared (= 0), Timer1 increments on every internal
FIGURE 12-1:
FIGURE 12-2:
DS41303B-page 142
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
T1OSO/T13CKI
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
T1OSO/T13CKI
Timer1 Operation
T1OSI
T1OSI
T1OSCEN
Timer1 Oscillator
T1CKPS<1:0>
T1SYNC
TMR1ON
Timer1 Oscillator
T1OSCEN
TIMER1 BLOCK DIAGRAM
TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
T1CKPS<1:0>
T1SYNC
TMR1ON
(1)
(1)
TMR1CS
TMR1CS
(CCP Special Event Trigger)
(CCP Special Event Trigger)
Clear TMR1
Clear TMR1
Advance Information
Internal
Clock
F
Clock
Internal
F
OSC
OSC
/4
/4
On/Off
1
0
1
0
Timer1 Clock Input
Timer1 Clock Input
Prescaler
1, 2, 4, 8
Prescaler
1, 2, 4, 8
instruction cycle (F
increments on every rising edge of either the Timer1
external clock input or the Timer1 oscillator, if enabled.
When the Timer1 oscillator is enabled, the digital
circuitry
RC0/T1OSO/T13CKI pins is disabled. This means the
values of TRISC<1:0> are ignored and the pins are
read as ‘0’.
2
2
TMR1L
TMR1L
associated
8
Sleep Input
Synchronize
Sleep Input
8
Synchronize
OSC
Detect
Detect
High Byte
High Byte
TMR1H
TMR1
TMR1
/4). When the bit is set, Timer1
8
with
© 2007 Microchip Technology Inc.
8
8
the
Internal Data Bus
1
0
1
0
Read TMR1L
Write TMR1L
RC1/T1OSI
on Overflow
on Overflow
TMR1IF
TMR1IF
Set
Set
Timer1
On/Off
Timer1
On/Off
and