PIC16CR58A Microchip Technology, PIC16CR58A Datasheet - Page 71

• Manufacturer Part Number: PIC16CR58A
• Description: ROM-Based 8-Bit CMOS Microcontroller Series
• Manufacturer: Microchip Technology

8.0
Timer1 is a 16-bit timer/counter consisting of two 8-bit
registers (TMR1H and TMR1L) which are readable and
writable. Register TMR1 (TMR1H:TMR1L) increments
from 0000h to FFFFh and rolls over to 0000h. The
TMR1 Interrupt, if enabled, is generated on overflow
which is latched in interrupt flag bit TMR1IF (PIR1<0>).
This interrupt can be enabled/disabled by setting/clear-
ing the TMR1 interrupt enable bit TMR1IE (PIE1<0>).
Timer1 can operate in one of two modes:
• As a timer
• As a counter
The operating mode is determined by clock select bit,
TMR1CS (T1CON<1>) (Figure 8-2).
In timer mode, Timer1 increments every instruction
cycle. In counter mode, it increments on every rising
edge of the external clock input.
Timer1 can be enabled/disabled by setting/clearing
control bit TMR1ON (T1CON<0>).
FIGURE 8-1:
Applicable Devices
61 62 62A R62 63 R63 64 64A R64 65 65A R65 66 67
1997 Microchip Technology Inc.
bit7
bit 7-6:
bit 5-4:
bit 3:
bit 2:
bit 1:
bit 0:
U-0
—
TIMER1 MODULE
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 Control bit
1 = Oscillator is enabled
0 = Oscillator is shut off
Note: The oscillator inverter and feedback resistor are turned off to eliminate power drain.
T1SYNC: Timer1 External Clock Input Synchronization Control bit
TMR1CS = 1
1 = Do not synchronize external clock input
0 = Synchronize external clock input
TMR1CS = 0
This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.
TMR1CS: Timer1 Clock Source Select bit
1 = External clock from T1OSI (on the rising edge) (See pinouts for pin with T1OSI function)
0 = Internal clock (Fosc/4)
TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1
U-0
—
T1CON: TIMER1 CONTROL REGISTER (ADDRESS 10h)
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC
R/W-0
R/W-0
R/W-0
R/W-0
Timer1 also has an internal “reset input”. This reset can
be generated by CCP1 or CCP2 (Capture/Compare/
PWM) module. See Section 10.0 for details. Figure 8-1
shows the Timer1 control register.
For the PIC16C62A/R62/63/R63/64A/R64/65A/R65/
R66/67, when the Timer1 oscillator is enabled
(T1OSCEN is set), the RC1 and RC0 pins become
inputs. That is, the TRISC<1:0> value is ignored.
For the PIC16C62/64/65, when the Timer1 oscillator is
enabled (T1OSCEN is set), RC1 pin becomes an input,
however the RC0 pin will have to be configured as an
input by setting the TRISC<0> bit.
The Timer1 module also has a software programmable
prescaler.
TMR1CS TMR1ON
R/W-0
R/W-0
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit,
- n = Value at POR reset
read as ‘0’
PIC16C6X
DS30234D-page 71