PIC18C242 MICROCHIP [Microchip Technology], PIC18C242 Datasheet - Page 97

• Manufacturer Part Number: PIC18C242
• Description: High-Performance Microcontrollers with 10-Bit A/D
• Manufacturer: MICROCHIP [Microchip Technology]

10.0
The Timer1 module timer/counter has the following fea-
tures:
• 16-bit timer/counter
• Readable and writable (Both registers)
• Internal or external clock select
• Interrupt on overflow from FFFFh to 0000h
• Reset from CCP module special event trigger
Register 10-1: T1CON: Timer1 Control Register
bit 7
bit 6
bit 5:4
bit 3
bit 2
bit 1
bit 0
(Two 8-bit registers; TMR1H and TMR1L)
7/99 Microchip Technology Inc.
TIMER1 MODULE
bit 7
RD16: 16-bit Read/Write Mode Enable bit
1 = Enables register Read/Write of TImer1 in one 16-bit operation
0 = Enables register Read/Write of Timer1 in two 8-bit operations
Unimplemented: Read as '0'
T1CKPS1:T1CKPS0: 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 Enable bit
1 = Timer1 Oscillator is enabled
0 = Timer1 Oscillator is shut off.
The oscillator inverter and feedback resistor are turned off to eliminate power drain
T1SYNC: Timer1 External Clock Input Synchronization Select bit
When TMR1CS = 1:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
When TMR1CS = 0:
This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.
TMR1CS: Timer1 Clock Source Select bit
1 = External clock from pin RC0/T1OSO/T13CKI (on the rising edge)
0 = Internal clock (F
TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1
Legend:
R = Readable bit
- n = Value at POR reset
R/W-0
RD16
U-0
—
OSC
T1CKPS1
/4)
R/W-0
W = Writable bit
’1’ = Bit is set
T1CKPS0
R/W-0
Preliminary
T1OSCEN
R/W-0
U = Unimplemented bit, read as ‘0’
’0’ = Bit is cleared
Figure 10-1 is a simplified block diagram of the Timer1
module.
Register 10-1 shows the Timer1 control register. This
register controls the operating mode of the Timer1
module as well as contains the Timer1 oscillator enable
bit (T1OSCEN). Timer1 can be enabled/disabled by
setting/clearing control bit TMR1ON (T1CON<0>).
T1SYNC
R/W-0
TMR1CS
x = Bit is unknown
R/W-0
PIC18CXX2
TMR1ON
bit 0
R/W-0
DS39026B-page 97