PIC16F636-I/P Microchip Technology Inc., PIC16F636-I/P Datasheet - Page 22

• Manufacturer Part Number: PIC16F636-I/P
• Description: 14 PIN, 3.5 KB FLASH, 128 RAM, 12 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F636-I/P

• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 12
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 14-pin PDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• Speed: 20 MHz
• Timers: 1-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC12F635/PIC16F636/639
2.2.2.1
The Status register, shown in Register 2-1, contains:
• the arithmetic status of the ALU
• the Reset status
• the bank select bits for data memory (SRAM)
The Status register can be the destination for any
instruction, like any other register. If the Status register is
the destination for an instruction that affects the Z, DC or
C bits, then the write to these three bits is disabled.
These bits are set or cleared according to the device
logic. Furthermore, the TO and PD bits are not writable.
Therefore, the result of an instruction with the Status
register as destination may be different than intended.
REGISTER 2-1:
DS41232B-page 20
bit 7
bit 6-5
bit 4
bit 3
bit 2
bit 1
bit 0
Status Register
STATUS – STATUS REGISTER (ADDRESS: 03h OR 83h)
bit 7
IRP: Register Bank Select bit (used for indirect addressing)
1 = Bank 2, 3 (100h-1FFh)
0 = Bank 0, 1 (00h-FFh)
RP<1:0>: Register Bank Select bits (used for direct addressing)
11 = Bank 3 (180h-1FFh)
10 = Bank 2 (100h-17Fh)
01 = Bank 1 (80h-FFh)
00 = Bank 0 (00h-7Fh)
Each bank is 128 bytes.
TO: Time-out bit
1 = After power-up, CLRWDT instruction or SLEEP instruction
0 = A WDT time-out occurred
PD: Power-down bit
1 = After power-up or by the CLRWDT instruction
0 = By execution of the SLEEP instruction
Z: Zero bit
1 = The result of an arithmetic or logic operation is zero
0 = The result of an arithmetic or logic operation is not zero
DC: Digit Carry/Borrow bit (ADDWF, ADDLW, SUBLW, SUBWF instructions)
For Borrow, the polarity is reversed.
1 = A carry-out from the 4th low-order bit of the result occurred
0 = No carry-out from the 4th low-order bit of the result
C: Carry/Borrow bit (ADDWF, ADDLW, SUBLW, SUBWF instructions)
1 = A carry-out from the Most Significant bit of the result occurred
0 = No carry-out from the Most Significant bit of the result occurred
Legend:
R = Readable bit
- n = Value at POR
Note:
R/W-0
IRP
For Borrow, the polarity is reversed. A subtraction is executed by adding the two’s
complement of the second operand. For rotate (RRF, RLF) instructions, this bit is
loaded with either the high-order or low-order bit of the source register.
R/W-0
RP1
R/W-0
RP0
Preliminary
W = Writable bit
‘1’ = Bit is set
R-1
TO
For example, CLRF STATUS, will clear the upper three
bits and set the Z bit. This leaves the Status register as
000u u1uu (where u = unchanged).
It is recommended, therefore, that only BCF, BSF, SWAPF
and MOVWF instructions are used to alter the Status
register, because these instructions do not affect any
Status bits. For other instructions not affecting any Status
bits, see Section 13.0 “Instruction Set Summary”.
Note 1: The C and DC bits operate as a Borrow
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
R-1
PD
and Digit Borrow out bit, respectively, in
subtraction. See the SUBLW and SUBWF
instructions for examples.
R/W-x
© 2005 Microchip Technology Inc.
Z
x = Bit is unknown
R/W-x
DC
R/W-x
C
bit 0