PIC16F87X_02 Datasheet, PDF (3/22 Pages) Microchip Technology – EEPROM Memory Programming Specification

2.0 PROGRAM MODE ENTRY
2.1 User Program Memory Map
The user memory space extends from 0x0000 to
0x1FFF (8K). In Programming mode, the program
memory space extends from 0x0000 to 0x3FFF, with
the first half (0x0000-0x1FFF) being user program
memory and the second half (0x2000-0x3FFF) being
configuration memory. The PC will increment from
0x0000 to 0x1FFF and wrap to 0x0000, 0x2000 to
0x3FFF and wrap around to 0x2000 (not to 0x0000).
Once in configuration memory, the highest bit of the PC
stays a ‘1’, thus always pointing to the configuration
memory. The only way to point to user program mem-
ory is to reset the part and re-enter Program/Verify
mode, as described in Section 2.4.
In the configuration memory space, 0x2000-0x200F
are physically implemented. However, only locations
0x2000 through 0x2007 are available. Other locations
are reserved. Locations beyond 0x200F will physically
access user memory (see Figure 2-1).
2.2 Data EEPROM Memory
The EEPROM data memory space is a separate block
of high endurance memory that the user accesses
using a special sequence of instructions. The amount
of data EEPROM memory depends on the device and
is shown below in number of bytes.
Device
PIC16F870
PIC16F871
PIC16F872
PIC16F873
PIC16F874
PIC16F876
PIC16F877
# of Bytes
64
64
64
128
128
256
256
PIC16F87X
The contents of data EEPROM memory have the capa-
bility to be embedded into the HEX file.
The programmer should be able to read data EEPROM
information from a HEX file and conversely (as an
option), write data EEPROM contents to a HEX file,
along with program memory information and configura-
tion bit information.
The 256 data memory locations are logically mapped
starting at address 0x2100. The format for data mem-
ory storage is one data byte per address location, LSB
aligned.
2.3 ID Locations
A user may store identification information (ID) in four
ID locations. The ID locations are mapped in [0x2000 :
0x2003]. It is recommended that the user use only the
four Least Significant bits of each ID location. In some
devices, the ID locations read out in an unscrambled
fashion after code protection is enabled. For these
devices, it is recommended that ID location is written as
“11 1111 1000 bbbb” where ‘bbbb’ is ID information.
In other devices, the ID locations read out normally,
even after code protection. To understand how the
devices behave, refer to Table 5-1.
To understand the scrambling mechanism after code
protection, refer to Section 4.0.
 2002 Microchip Technology Inc.
DS39025F-page 3