PIC18F4520-I/P Microchip Technology Inc., PIC18F4520-I/P Datasheet - Page 125

• Manufacturer Part Number: PIC18F4520-I/P
• Description: 40 Pin, 32 KB Flash, 1536 RAM, 36 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F4520-I/P

• A/d Inputs: 13-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 10 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 36
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 32K Bytes
• Ram Size: 1.5K Bytes
• Speed: 40 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

11.0
The Timer0 module incorporates the following features:
• Software selectable operation as a timer or
• Readable and writable registers
• Dedicated 8-bit, software programmable
• Selectable clock source (internal or external)
• Edge select for external clock
• Interrupt-on-overflow
REGISTER 11-1:
 2004 Microchip Technology Inc.
counter in both 8-bit or 16-bit modes
prescaler
TIMER0 MODULE
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2-0
T0CON: TIMER0 CONTROL REGISTER
bit 7
TMR0ON: Timer0 On/Off Control bit
1 = Enables Timer0
0 = Stops Timer0
T08BIT: Timer0 8-bit/16-bit Control bit
1 = Timer0 is configured as an 8-bit timer/counter
0 = Timer0 is configured as a 16-bit timer/counter
T0CS: Timer0 Clock Source Select bit
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock (CLKO)
T0SE: Timer0 Source Edge Select bit
1 = Increment on high-to-low transition on T0CKI pin
0 = Increment on low-to-high transition on T0CKI pin
PSA: Timer0 Prescaler Assignment bit
1 = TImer0 prescaler is NOT assigned. Timer0 clock input bypasses prescaler.
0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output.
T0PS2:T0PS0: Timer0 Prescaler Select bits
111 = 1:256 prescale value
110 = 1:128 prescale value
101 = 1:64 prescale value
100 = 1:32 prescale value
011 = 1:16 prescale value
010 = 1:8 prescale value
001 = 1:4 prescale value
000 = 1:2 prescale value
Legend:
R = Readable bit
-n = Value at POR
TMR0ON
R/W-1
T08BIT
R/W-1
PIC18F2420/2520/4420/4520
R/W-1
T0CS
Preliminary
W = Writable bit
‘1’ = Bit is set
R/W-1
T0SE
The T0CON register (Register 11-1) controls all
aspects of the module’s operation, including the
prescale selection. It is both readable and writable.
A simplified block diagram of the Timer0 module in 8-bit
mode is shown in Figure 11-1. Figure 11-2 shows a
simplified block diagram of the Timer0 module in 16-bit
mode.
R/W-1
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
PSA
T0PS2
R/W-1
x = Bit is unknown
T0PS1
R/W-1
DS39631A-page 123
T0PS0
R/W-1
bit 0