PIC16C5X
4.2.2
SPECIAL FUNCTION REGISTERS
The special registers can be classified into two sets.
The special function registers associated with the
“core” functions are described in this section. Those
related to the operation of the peripheral features are
described in the section for each peripheral feature.
The Special Function Registers are registers used by
the CPU and peripheral functions to control the
operation of the device (Table 4-1).
TABLE 4-1:
SPECIAL FUNCTION REGISTER SUMMARY
Value on
Power-On
Reset
Value on
MCLR and
WDT Reset
Address
Name
TRIS
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
N/A
N/A
00h
01h
I/O control registers (TRISA, TRISB, TRISC)
1111 1111 1111 1111
--11 1111 --11 1111
xxxx xxxx uuuu uuuu
xxxx xxxx uuuu uuuu
OPTION
INDF
Contains control bits to configure Timer0 and Timer0/WDT prescaler
Uses contents of FSR to address data memory (not a physical register)
8-bit real-time clock/counter
TMR0
(1)
02h
PCL
Low order 8 bits of PC
1111 1111 1111 1111
0001 1xxx 000q quuu
1xxx xxxx 1uuu uuuu
---- xxxx ---- uuuu
xxxx xxxx uuuu uuuu
03h
04h
05h
06h
STATUS
FSR
PA2
PA1
PA0
TO
PD
Z
DC
C
Indirect data memory address pointer
PORTA
PORTB
—
—
—
—
RA3
RB3
RA2
RB2
RA1
RB1
RA0
RB0
RB7
RB6
RB5
RB4
(2)
07h
PORTC
RC7
RC6
RC5
RC4
RC3
RC2
RC1
RC0
xxxx xxxx uuuu uuuu
Legend: Shaded boxes = unimplemented or unused, –= unimplemented, read as '0' (if applicable)
x= unknown, u= unchanged, q= see the tables in Section 7.7 for possible values.
Note 1: The upper byte of the Program Counter is not directly accessible. See Section 4.5
for an explanation of how to access these bits.
2: File address 07h is a general purpose register on the PIC16C52, PIC16C54s, PIC16CR54s, PIC16C56s, PIC16CR56s,
PIC16C58s and PIC16CR58s.
1998 Microchip Technology Inc.
Preliminary
DS30453B-page 19
MICROCHIP [ MICROCHIP ]
