PIC16CR58A Microchip Technology, PIC16CR58A Datasheet - Page 20

• Manufacturer Part Number: PIC16CR58A
• Description: ROM-Based 8-Bit CMOS Microcontroller Series
• Manufacturer: Microchip Technology

PIC16C5X
4.3
This register contains the arithmetic status of the ALU,
the RESET status, and the page preselect bits for
program memories larger than 512 words.
The STATUS register can be the destination for any
instruction, as with 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
FIGURE 4-8:
DS30453B-page 20
bit7
bit 7:
bit 6-5:
bit 4:
bit 3:
bit 2:
bit 1:
bit 0:
R/W-0
PA2
STATUS Register
PA2: This bit unused at this time.
Use of the PA2 bit as a general purpose read/write bit is not recommended, since this may affect upward
compatibility with future products.
PA1:PA0: Program page preselect bits (PIC16C56s/CR56s)(PIC16C57s/CR57s)(PIC16C58s/CR58s)
00 = Page 0 (000h - 1FFh) - PIC16C56s/CR56s, PIC16C57s/CR57s, PIC16C58s/CR58s
01 = Page 1 (200h - 3FFh) - PIC16C56s/CR56s, PIC16C57s/CR57s, PIC16C58s/CR58s
10 = Page 2 (400h - 5FFh) - PIC16C57s/CR57s, PIC16C58s/CR58s
11 = Page 3 (600h - 7FFh) - PIC16C57s/CR57s, PIC16C58s/CR58s
Each page is 512 words.
Using the PA1:PA0 bits as general purpose read/write bits in devices which do not use them for program
page preselect is not recommended since this may affect upward compatibility with future products.
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 (for ADDWF and SUBWF instructions)
ADDWF
1 = A carry from the 4th low order bit of the result occurred
0 = A carry from the 4th low order bit of the result did not occur
SUBWF
1 = A borrow from the 4th low order bit of the result did not occur
0 = A borrow from the 4th low order bit of the result occurred
C: Carry/borrow bit (for ADDWF, SUBWF and RRF, RLF instructions)
ADDWF
1 = A carry occurred
0 = A carry did not occur
R/W-0
PA1
6
STATUS REGISTER (ADDRESS:03h)
R/W-0
PA0
5
R-1
TO
4
SUBWF
1 = A borrow did not occur
0 = A borrow occurred
R-1
PD
3
Preliminary
R/W-x
Z
2
not writable. Therefore, the result of an instruction with
the STATUS register as destination may be different
than intended.
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 and
MOVWF instructions be used to alter the STATUS
register because these instructions do not affect the Z,
DC or C bits from the STATUS register. For other
instructions, which do affect STATUS bits, see
Section 8.0, Instruction Set Summary.
R/W-x
DC
1
RRF or RLF
Load bit with LSb or MSb, respectively
R/W-x
C
bit0
R = Readable bit
W = Writable bit
- n = Value at POR reset
1998 Microchip Technology Inc.