PIC16F785-I/P Microchip Technology Inc., PIC16F785-I/P Datasheet - Page 18

• Manufacturer Part Number: PIC16F785-I/P
• Description: MCU, 8-Bit, 2KW Flash, 128 RAM, 18 I/O, DIP-20
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F785-I/P

• A/d Inputs: 12-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 17
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 20-pin PDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC16F785/HV785
2.2.2.2
The Option register is a readable and writable register,
which contains various control bits to configure the
TMR0/WDT prescaler, the external RA2/INT interrupt,
the TMR0 and the weak pull-ups on PORTA.
REGISTER 2-2:
DS41249D-page 16
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2-0
OPTION_REG Register
OPTION_REG: OPTION REGISTER (ADDRESS: 81h OR 181h)
bit 7
RAPU: PORTA Pull-up Enable bit
1 = PORTA pull-ups are disabled
0 = PORTA pull-ups are enabled by individual port latch values in WPUA register
INTEDG: Interrupt Edge Select bit
1 = Interrupt on rising edge of RA2/AN2/T0CKI/INT/C1OUT pin
0 = Interrupt on falling edge of RA2/AN2/T0CKI/INT/C1OUT pin
T0CS: TMR0 Clock Source Select bit
1 = Transition on RA2/AN2/T0CKI/INT/C1OUT pin
0 = Internal instruction cycle clock (CLKOUT)
T0SE: TMR0 Source Edge Select bit
1 = Increment on high-to-low transition on RA2/AN2/T0CKI/INT/C1OUT pin
0 = Increment on low-to-high transition on RA2/AN2/T0CKI/INT/C1OUT pin
PSA: Prescaler Assignment bit
1 = Prescaler is assigned to the WDT
0 = Prescaler is assigned to the Timer0 module
PS<2:0>: Prescaler Rate Select bits
Legend:
R = Readable bit
-n = Value at POR
R/W-1
RAPU
Note 1: A dedicated 16-bit WDT postscaler is available for the PIC16F785/HV785.
Bit Value TMR0 Rate WDT Rate
See Section 15.5 “Watchdog Timer (WDT)” for more information.
000
001
010
011
100
101
110
111
INTEDG
R/W-1
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
1 : 256
R/W-1
T0CS
Preliminary
W = Writable bit
‘1’ = Bit is set
1 : 1
1 : 2
1 : 4
1 : 8
1 : 16
1 : 32
1 : 64
1 : 128
R/W-1
T0SE
Note:
(1)
R/W-1
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
PSA
To achieve a 1:1 prescaler assignment for
TMR0, assign the prescaler to the WDT by
setting PSA bit to ‘1’ (OPTION_REG<3>).
See Section 5.4 “Prescaler”.
R/W-1
PS2
© 2006 Microchip Technology Inc.
x = Bit is unknown
R/W-1
PS1
R/W-1
PS0
bit 0