PIC18F25J50 MICROCHIP [Microchip Technology], PIC18F25J50 Datasheet - Page 199

• Manufacturer Part Number: PIC18F25J50
• Description: 28/44-Pin, Low-Power, High-Performance USB Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

13.0
The Timer1 timer/counter module incorporates these
features:
• Software-selectable operation as a 16-bit timer or
• Readable and writable 8-bit registers (TMR1H
• Selectable clock source (internal or external) with
• Interrupt-on-overflow
• Reset on ECCP Special Event Trigger
• Device clock status flag (T1RUN)
• Timer with gated control
REGISTER 13-1:
 2011 Microchip Technology Inc.
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7-6
bit 5-4
bit 3
bit 2
Note 1:
TMR1CS1
counter
and TMR1L)
device clock or Timer1 oscillator internal options
R/W-0
2:
TIMER1 MODULE
The F
features.
The Timer1 oscillator crystal driver is powered whenever T1OSCEN (T1CON) or T3OSCEN (T3CON) = 1.
The circuit is enabled by the logical OR of these two bits. When disabled, the inverter and feedback resistor
are disabled to eliminate power drain. The TMR1ON and TMR3ON bits do not have to be enabled to power
up the crystal driver.
TMR1CS<1:0>: Timer1 Clock Source Select bits
10 = Timer1 clock source is the T1OSC or T1CKI pin
01 = Timer1 clock source is the system clock (F
00 = Timer1 clock source is the instruction clock (F
T1CKPS<1:0>: Timer1 Input Clock Prescale Select bits
11 = 1:8 Prescale value
10 = 1:4 Prescale value
01 = 1:2 Prescale value
00 = 1:1 Prescale value
T1OSCEN: Timer1 Oscillator Source Select bit
When TMR1CS<1:0> = 10:
1 = Power up the Timer1 crystal driver and supply the Timer1 clock from the crystal output
0 = Timer1 crystal driver is off, Timer1 clock is from the T1CKI input pin
When TMR1CS<1:0> = 0x:
1 = Power up the Timer1 crystal driver
0 = Timer1 crystal driver is off
T1SYNC: Timer1 External Clock Input Synchronization Select bit
TMR1CS<1:0> = 10:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
TMR1CS<1:0> = 0x:
This bit is ignored. Timer1 uses the internal clock when TMR1CS<1:0> = 0x.
TMR1CS0
OSC
R/W-0
clock source should not be selected if the timer will be used with the ECCP capture/compare
T1CON: TIMER1 CONTROL REGISTER (ACCESS FCDh)
W = Writable bit
‘1’ = Bit is set
T1CKPS1
R/W-0
(2)
T1CKPS0
R/W-0
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
PIC18F46J50 FAMILY
T1OSCEN
Figure 13-1
Timer1 module.
The module incorporates its own low-power oscillator
to provide an additional clocking option. The Timer1
oscillator can also be used as a low-power clock source
for the microcontroller in power-managed operation.
Timer1 is controlled through the T1CON Control
register
Oscillator Enable bit (T1OSCEN). Timer1 can be
enabled or disabled by setting or clearing control bit,
TMR1ON (T1CON<0>).
The F
be used with the ECCP capture/compare features. If the
timer will be used with the capture or compare features,
always select one of the other timer clocking options.
OSC
R/W-0
OSC
)
(1)
OSC
/4)
(Register
clock source (TMR1CS<1:0> = 01) should not
displays a simplified block diagram of the
T1SYNC
R/W-0
13-1). It also contains the Timer1
(2)
x = Bit is unknown
R/W-0
RD16
DS39931D-page 199
TMR1ON
R/W-0
bit 0