PIC18F2450/4450
DS39760A-page 190
Advance Information
2006 Microchip Technology Inc.
18.1
Configuration Bits
The Configuration bits can be programmed (read as
‘0’) or left unprogrammed (read as ‘1’) to select various
device configurations. These bits are mapped starting
at program memory location 300000h.
The user will note that address 300000h is beyond the
user program memory space. In fact, it belongs to the
configuration memory space (300000h-3FFFFFh), which
can only be accessed using table reads and table writes.
Programming the Configuration registers is done in a
manner similar to programming the Flash memory. The
WR bit in the EECON1 register starts a self-timed write
to the Configuration register. In normal operation mode,
a TBLWT instruction, with the TBLPTR pointing to the
Configuration register, sets up the address and the
data for the Configuration register write. Setting the WR
bit starts a long write to the Configuration register. The
Configuration registers are written a byte at a time. To
write or erase a configuration cell, a TBLWT instruction
can write a ‘1’ or a ‘0’ into the cell. For additional details
TABLE 18-1:
CONFIGURATION BITS AND DEVICE IDs
File Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Default/
Unprogrammed
Value
300000h
CONFIG1L
—
USBDIV CPUDIV1 CPUDIV0
PLLDIV2
PLLDIV1
PLLDIV0
--00 0000
300001h
CONFIG1H
IESO
FCMEN
—
FOSC3
FOSC2
FOSC1
FOSC0
00-- 0101
300002h
CONFIG2L
—
VREGEN
BORV1
BORV0
BOREN1
BOREN0 PWRTEN
--01 1111
300003h
CONFIG2H
—
WDTPS3
WDTPS2
WDTPS1
WDTPS0
WDTEN
---1 1111
300005h
CONFIG3H
MCLRE
—
LPT1OSC PBADEN
—
1--- -01-
300006h
CONFIG4L
DEBUG
XINST
ICPRT(2)
—BBSIZ
LVP
—STVREN
100- 01-1
300008h
CONFIG5L
—
—CP1
CP0
---- --11
300009h
CONFIG5H
—CPB
—
-1-- ----
30000Ah
CONFIG6L
—
—WRT1
WRT0
---- --11
30000Bh
CONFIG6H
—WRTB
WRTC
—
-11- ----
30000Ch
CONFIG7L
—
EBTR1
EBTR0
---- --11
30000Dh
CONFIG7H
—EBTRB
—
-1-- ----
3FFFFEh
DEVID1
DEV2
DEV1
DEV0
REV4
REV3
REV2
REV1
REV0
xxxx xxxx
(1)
3FFFFFh
DEVID2
DEV10
DEV9
DEV8
DEV7
DEV6
DEV5
DEV4
DEV3
0001 0010
(1)
Legend:
x
= unknown, u = unchanged, - = unimplemented. Shaded cells are unimplemented, read as ‘0’.
Note
1:
by the user.
2:
Available only on PIC18F4450 devices in 44-pin TQFP packages. Always leave this bit clear in all other devices.
