PIC18F87K90T-I/PT Microchip Technology, PIC18F87K90T-I/PT Datasheet - Page 185

• Manufacturer Part Number: PIC18F87K90T-I/PT
• Description: 128kB Flash, 4kB RAM, 1kB EE, 16MIPS, NanoWatt XLP, LCD, 5V 80 TQFP 12x12x1mm T/
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F87K90T-I/PT

• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 128 KB
• Data Ram Size: 4 KB
• Interface Type: I2C, SPI
• Maximum Clock Frequency: 64 MHz
• Number Of Timers: 11
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 125 C
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12 bit, 24 Channel
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 64MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 69
• Eeprom Size: 1K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 24x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TQFP
• Lead Free Status / Rohs Status: Details

12.3
An 8-bit counter is available as a prescaler for the Timer0
module. The prescaler is not directly readable or writable.
Its value is set by the PSA and T0PS<2:0> bits
(T0CON<3:0>),
assignment and prescale ratio.
Clearing the PSA bit assigns the prescaler to the
Timer0 module. When it is assigned, prescale values
from 1:2 through 1:256, in power-of-two increments,
are selectable.
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (for example, CLRF TMR0,
MOVWF TMR0, BSF TMR0) clear the prescaler count.
TABLE 12-1:
 2009-2011 Microchip Technology Inc.
TMR0L
TMR0H
INTCON
T0CON
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by Timer0.
Note:
Name
Prescaler
Writing to TMR0 when the prescaler is
assigned to Timer0 will clear the prescaler
count but will not change the prescaler
assignment.
Timer0 Register Low Byte
Timer0 Register High Byte
GIE/GIEH PEIE/GIEL TMR0IE
TMR0ON
Bit 7
which
REGISTERS ASSOCIATED WITH TIMER0
determine
T08BIT
Bit 6
the
T0CS
Bit 5
prescaler
INT0IE
T0SE
Bit 4
PIC18F87K90 FAMILY
12.3.1
The prescaler assignment is fully under software
control and can be changed “on-the-fly” during program
execution.
12.4
The TMR0 interrupt is generated when the TMR0
register overflows from FFh to 00h in 8-bit mode, or
from FFFFh to 0000h in 16-bit mode. This overflow sets
the TMR0IF flag bit. The interrupt can be masked by
clearing the TMR0IE bit (INTCON<5>). Before re-
enabling the interrupt, the TMR0IF bit must be cleared
in software by the Interrupt Service Routine (ISR).
Since Timer0 is shut down in Sleep mode, the TMR0
interrupt cannot awaken the processor from Sleep.
RBIE
Bit 3
PSA
Timer0 Interrupt
TMR0IF
T0PS2
SWITCHING PRESCALER
ASSIGNMENT
Bit 2
INT0IF
T0PS1
Bit 1
T0PS0
RBIF
Bit 0
DS39957D-page 185
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Values
Reset
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