PIC12C67X and PIC12CE67X
2.0
2.1
PROGRAM MODE ENTRY
User Program Memory Map
The user memory space extends from 0x0000 to
0x1FFF (8K). Table 2-1 shows actual implementation
of program memory in the PIC12C67X family.
In the configuration memory space, 0x2000-0x20FF
are utilized. When in configuration memory, as in the
user memory, the 0x2000-0x2XFF segment is repeat-
edly accessed as the PC exceeds 0x2XFF (see
A user may store identification information (ID) in four
ID locations. The ID locations are mapped in [0x2000 :
0x2003].
Note 1:
All other locations in PIC configuration
memory are reserved and should not be
programmed.
Note 2:
Due to the secure nature of the on-board
EEPROM
memory
in
the
PIC12CE673/674, it can be accessed only
by the user program.
TABLE 2-1:
IMPLEMENTATION OF
PROGRAM MEMORY IN THE
PIC12C67X
Program Memory Size
0x000 - 0x3FF (1K)
0x000 - 0x7FF (2K)
Device
PIC12C671/
PIC12CE673
PIC12C672/
PIC12CE674
When the PC reaches the last location of the imple-
mented program memory, it will wrap around and
address a location within the physically implemented
memory (see Figure 2-1).
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 0x000 or 0x2000 to 0x3FFF and
wrap around to 0x2000 (not to 0x0000). Once in con-
figuration 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 memory is to reset
the part and reenter program/verify mode, as described
in Section 2.2.
The last location of the program memory space holds
the factory programmed oscillator calibration value.
This location should not be programmed except when
blank (a non-blank value should not cause the device
to fail a blank check). If blank, the programmer should
program it to a RETLW XX statement where "XX" is the
calibration value.
DS40175A-page 2
©
1998 Microchip Technology Inc.
MICROCHIP [ MICROCHIP TECHNOLOGY ]
