Datasheet
PIC18F2XXX/4XXX FAMILY
DS39622L-page 10 2010 Microchip Technology Inc.
In addition to the code memory space, there are three
blocks that are accessible to the user through Table
Reads and Table Writes. Their locations in the memory
map are shown in Figure 2-9.
Users may store identification information (ID) in eight ID
registers. These ID registers are mapped in addresses,
200000h through 200007h. The ID locations read out
normally, even after code protection is applied.
Locations, 300000h through 30000Dh, are reserved for
the Configuration bits. These bits select various device
options and are described in Section 5.0 “Configura-
tion Word”. These Configuration bits read out
normally, even after code protection.
Locations, 3FFFFEh and 3FFFFFh, are reserved for
the Device ID bits. These bits may be used by the
programmer to identify what device type is being
programmed and are described in Section 5.0 “Con-
figuration Word”. These Device ID bits read out
normally, even after code protection.
2.3.1 MEMORY ADDRESS POINTER
Memory in the address space, 0000000h to 3FFFFFh,
is addressed via the Table Pointer register, which is
comprised of three pointer registers:
• TBLPTRU at RAM address 0FF8h
• TBLPTRH at RAM address 0FF7h
• TBLPTRL at RAM address 0FF6h
The 4-bit command, ‘0000’ (core instruction), is used to
load the Table Pointer prior to using many read or write
operations.
FIGURE 2-9: CONFIGURATION AND ID LOCATIONS FOR PIC18F2XXX/4XXX FAMILY DEVICES
TBLPTRU TBLPTRH TBLPTRL
Addr[21:16] Addr[15:8] Addr[7:0]
ID Location 1 200000h
ID Location 2 200001h
ID Location 3 200002h
ID Location 4 200003h
ID Location 5 200004h
ID Location 6 200005h
ID Location 7 200006h
ID Location 8 200007h
CONFIG1L 300000h
CONFIG1H 300001h
CONFIG2L 300002h
CONFIG2H 300003h
CONFIG3L 300004h
CONFIG3H 300005h
CONFIG4L 300006h
CONFIG4H 300007h
CONFIG5L 300008h
CONFIG5H 300009h
CONFIG6L 30000Ah
CONFIG6H 30000Bh
CONFIG7L 30000Ch
CONFIG7H 30000Dh
Device ID1 3FFFFEh
Device ID2 3FFFFFh
Note: Sizes of memory areas are not to scale.
000000h
1FFFFFh
3FFFFFh
01FFFFh
Code Memory
Unimplemented
Read as ‘0’
Configuration
and ID
Space
2FFFFFh