PIC18F452-I/LG Microchip Technology, PIC18F452-I/LG Datasheet - Page 110

• Manufacturer Part Number: PIC18F452-I/LG
• Description: IC MCU FLASH 16KX16 W/AD 44PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F452-I/LG

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-PLCC
• For Use With: XLT44L2 - SOCKET TRAN ICE 44PLCCDVA16XL441 - ADAPTER DEVICE ICE 44PLCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIC18FXX2
11.1
Timer1 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, TMR1CS (T1CON<1>).
FIGURE 11-1:
FIGURE 11-2:
DS39564C-page 108
T13CKI/T1OSO
Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
T1CKI/T1OSO
T1OSI
TMR1IF
Overflow
Interrupt
Flag bit
Data Bus<7:0>
Timer1 Operation
Write TMR1L
Read TMR1L
TMR1IF
Overflow
Interrupt
Flag Bit
T1OSI
TIMER1 BLOCK DIAGRAM: 16-BIT READ/WRITE MODE
TIMER1 BLOCK DIAGRAM
8
T1OSC
High Byte
TMR1H
Timer 1
8
TMR1H
T1OSC
8
TMR1
TMR1
Oscillator
Enable
T1OSCEN
T1OSCEN
Enable
Oscillator
TMR1L
TMR1L
8
(1)
CLR
(1)
CLR
Clock
Internal
F
OSC
Clock
F
Internal
OSC
/4
TMR1ON
CCP Special Event Trigger
On/Off
/4
TMR1CS
TMR1ON
CCP Special Event Trigger
on/off
1
0
When TMR1CS = 0, Timer1 increments every instruc-
tion cycle. When TMR1CS = 1, Timer1 increments on
every rising edge of the external clock input or the
Timer1 oscillator, if enabled.
When the Timer1 oscillator is enabled (T1OSCEN is
set), the RC1/T1OSI and RC0/T1OSO/T1CKI pins
become inputs. That is, the TRISC<1:0> value is
ignored, and the pins are read as ‘0’.
Timer1 also has an internal “RESET input”. This
RESET can be generated by the CCP module
(Section 14.0).
TMR1CS
1
0
T1CKPS1:T1CKPS0
T1SYNC
Prescaler
1, 2, 4, 8
T1CKPS1:T1CKPS0
T1SYNC
Prescaler
0
1
1, 2, 4, 8
2
1
0
2
© 2006 Microchip Technology Inc.
Synchronized
Clock Input
Synchronize
SLEEP Input
Synchronized
Clock Input
Synchronize
SLEEP Input
det
det