PIC18F4550-I/P Microchip Technology Inc., PIC18F4550-I/P Datasheet - Page 132

• Manufacturer Part Number: PIC18F4550-I/P
• Description: 40 PIN, 32 KB FLASH, 2048 RAM, FS-USB 2.0
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F4550-I/P

• A/d Inputs: 13-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 12 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 34
• Interface: I2C/SPI/UART/USART/USB
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 32K Bytes
• Ram Size: 2K Bytes
• Speed: 48 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F2455/2550/4455/4550
12.1
Timer1 can operate in one of these modes:
• Timer
• Synchronous Counter
• Asynchronous Counter
The operating mode is determined by the clock select
bit, TMR1CS (T1CON<1>). When TMR1CS is cleared
(= 0), Timer1 increments on every internal instruction
FIGURE 12-1:
FIGURE 12-2:
DS39632C-page 130
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
T1OSO/T13CKI
T1OSO/T13CKI
Timer1 Operation
T1OSI
T1OSI
Timer1 Oscillator
Timer1 Oscillator
TIMER1 BLOCK DIAGRAM
TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
T1OSCEN
T1CKPS1:T1CKPS0
T1SYNC
TMR1ON
T1OSCEN
T1CKPS1:T1CKPS0
T1SYNC
TMR1ON
(1)
(1)
TMR1CS
TMR1CS
(CCP Special Event Trigger)
(CCP Special Event Trigger)
Clear TMR1
Clear TMR1
Clock
Clock
Internal
Internal
F
F
OSC
OSC
/4
/4
Preliminary
On/Off
1
0
1
0
Prescaler
Prescaler
1, 2, 4, 8
1, 2, 4, 8
cycle (F
on every rising edge of the Timer1 external clock input
or the Timer1 oscillator, if enabled.
When Timer1 is enabled, the RC1/T1OSI/UOE and
RC0/T1OSO/T13CKI pins become inputs. This means
the values of TRISC<1:0> are ignored and the pins are
read as ‘0’.
2
2
OSC
TMR1L
TMR1L
/4). When the bit is set, Timer1 increments
8
8
Synchronize
Synchronize
Sleep Input
Sleep Input
Detect
Detect
High Byte
High Byte
TMR1H
TMR1
TMR1
8
© 2006 Microchip Technology Inc.
8
8
1
0
1
0
Set
TMR1IF
on Overflow
Read TMR1L
Write TMR1L
Internal Data Bus
Set
TMR1IF
on Overflow
Timer1
Timer1
On/Off
On/Off