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PIC17C4X
DS30412B-page 34
1996 Microchip Technology Inc.
TABLE 6-3:
SPECIAL FUNCTION REGISTERS
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
Power-on
Reset
Value on all
other
resets (3)
Unbanked
00h
INDF0
Uses contents of FSR0 to address data memory (not a physical register)
---- ----
---- ----
01h
FSR0
Indirect data memory address pointer 0
xxxx xxxx
uuuu uuuu
02h
PCL
Low order 8-bits of PC
0000 0000
0000 0000
03h
(1)
PCLATH
Holding register for upper 8-bits of PC
0000 0000
uuuu uuuu
04h
ALUSTA
FS3
FS2
FS1
FS0
OV
Z
DC
C
1111 xxxx
1111 uuuu
05h
T0STA
INTEDG
T0SE
T0CS
PS3
PS2
PS1
PS0
—
0000 000-
0000 000-
06h
(2)
CPUSTA
—
—
STKAV
GLINTD
TO
PD
—
—
--11 11--
--11 qq--
07h
INTSTA
PEIF
T0CKIF
T0IF
INTF
PEIE
T0CKIE
T0IE
INTE
0000 0000
0000 0000
08h
INDF1
Uses contents of FSR1 to address data memory (not a physical register)
---- ----
---- ----
09h
FSR1
Indirect data memory address pointer 1
xxxx xxxx
uuuu uuuu
0Ah
WREG
Working register
xxxx xxxx
uuuu uuuu
0Bh
TMR0L
TMR0 register; low byte
xxxx xxxx
uuuu uuuu
0Ch
TMR0H
TMR0 register; high byte
xxxx xxxx
uuuu uuuu
0Dh
TBLPTRL
Low byte of program memory table pointer
(4)
(4)
0Eh
TBLPTRH
High byte of program memory table pointer
(4)
(4)
0Fh
BSR
Bank select register
0000 0000
0000 0000
Bank 0
10h
PORTA
RBPU
—
RA5
RA4
RA3
RA2
RA1/T0CKI
RA0/INT
0-xx xxxx
0-uu uuuu
11h
DDRB
Data direction register for PORTB
1111 1111
1111 1111
12h
PORTB
PORTB data latch
xxxx xxxx
uuuu uuuu
13h
RCSTA
SPEN
RX9
SREN
CREN
—
FERR
OERR
RX9D
0000 -00x
0000 -00u
14h
RCREG
Serial port receive register
xxxx xxxx
uuuu uuuu
15h
TXSTA
CSRC
TX9
TXEN
SYNC
—
—
TRMT
TX9D
0000 --1x
0000 --1u
16h
TXREG
Serial port transmit register
xxxx xxxx
uuuu uuuu
17h
SPBRG
Baud rate generator register
xxxx xxxx
uuuu uuuu
Bank 1
10h
DDRC
Data direction register for PORTC
1111 1111
1111 1111
11h
PORTC
RC7/
AD7
RC6/
AD6
RC5/
AD5
RC4/
AD4
RC3/
AD3
RC2/
AD2
RC1/
AD1
RC0/
AD0
xxxx xxxx
uuuu uuuu
12h
DDRD
Data direction register for PORTD
1111 1111
1111 1111
13h
PORTD
RD7/
AD15
RD6/
AD14
RD5/
AD13
RD4/
AD12
RD3/
AD11
RD2/
AD10
RD1/
AD9
RD0/
AD8
xxxx xxxx
uuuu uuuu
14h
DDRE
Data direction register for PORTE
---- -111
---- -111
15h
PORTE
—
—
—
—
—
RE2/WR
RE1/OE
RE0/ALE
---- -xxx
---- -uuu
16h
PIR
RBIF
TMR3IF
TMR2IF
TMR1IF
CA2IF
CA1IF
TXIF
RCIF
0000 0010
0000 0010
17h
PIE
RBIE
TMR3IE
TMR2IE
TMR1IE
CA2IE
CA1IE
TXIE
RCIE
0000 0000
0000 0000
Legend:
Note 1:
x = unknown, u = unchanged, - = unimplemented read as '0', q - value depends on condition. Shaded cells are unimplemented, read as '0'.
The upper byte of the program counter is not directly accessible. PCLATH is a holding register for PC<15:8> whose contents are updated
from or transferred to the upper byte of the program counter.
The TO and PD status bits in CPUSTA are not affected by a MCLR reset.
Other (non power-up) resets include: external reset through MCLR and the Watchdog Timer Reset.
The following values are for both TBLPTRL and TBLPTRH:
All PIC17C4X devices (Power-on Reset 0000 0000) and (All other resets 0000 0000)
except the PIC17C42 (Power-on Reset xxxx xxxx) and (All other resets uuuu uuuu)
The PRODL and PRODH registers are not implemented on the PIC17C42.
2:
3:
4:
5: