PIC16F876A-E/SS Microchip Technology, PIC16F876A-E/SS Datasheet - Page 487

• Manufacturer Part Number: PIC16F876A-E/SS
• Description: 28 PIN, 14KB ENH FLASH, 368 RAM, 22 I/O,
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F876A-E/SS

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 28-SSOP
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 368 B
• Interface Type: I2C, SPI, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 1 x 16 bit
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163022, DV164120
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 5 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Section 26. Watchdog Timer and Sleep Mode
26.2
1997 Microchip Technology Inc.
Control Register
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2:0
The OPTION_REG register is a readable and writable register which contains various control bits
to configure the TMR0 prescaler/WDT postscaler, the External INT Interrupt, TMR0, and the
weak pull-ups on PORTB.
Register 26-1: OPTION_REG Register
bit 7
RBPU
1 = Weak pull-ups are disabled
0 = Weak pull-ups are enabled by individual port latch values
INTEDG: Interrupt Edge Select bit
1 = Interrupt on rising edge of INT pin
0 = Interrupt on falling edge of INT pin
T0CS: TMR0 Clock Source Select bit
1 = Transition on T0CKI pin
0 = Internal instruction cycle clock (CLKOUT)
T0SE: TMR0 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: Prescaler Assignment bit
1 = Prescaler is assigned to the WDT
0 = Prescaler is assigned to the Timer0 module
PS2:PS0: TMR0 Prescaler/WDT Postscaler Rate Select bits
Bit Value
Legend
R = Readable bit
U = Unimplemented bit, read as ‘0’
RBPU
R/W-1
Note:
Note 1: Some devices call this bit GPPU. Devices that have the RBPU bit, have the weak
000
001
010
011
100
101
110
111
(1)
(1)
: Weak Pull-up Enable bit
To achieve a 1:1 prescaler assignment for the TMR0 register, assign the prescaler
to the Watchdog Timer.
TMR0 Rate
pull-ups on PORTB, while devices that have the GPPU have the weak pull-ups on
the GP Port.
INTEDG
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
1 : 256
R/W-1
WDT Rate
W = Writable bit
1 : 1
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
R/W-1
T0CS
R/W-1
T0SE
- n = Value at POR reset
R/W-1
PSA
R/W-1
PS2
R/W-1
PS1
DS31026A-page 26-3
bit 0
R/W-1
PS0
26