ST6255C Datasheet, PDF (6/84 Pages) STMicroelectronics – 8-bit MCUs with ADC, safe reset, auto-reload timer, EEPROM and SPI

ST6255C ST6265C ST6265B
MEMORY MAP (Cont’d)
1.3.2 Program Space
Program Space comprises the instructions to be
executed, the data required for immediate ad-
dressing mode instructions, the reserved factory
test area and the user vectors. Program Space is
addressed via the 12-bit Program Counter register
(PC register).
Program Memory Protection
The Program Memory in OTP or EPROM devices
can be protected against external readout of mem-
ory by selecting the READOUT PROTECTION op-
tion in the option byte.
In the EPROM parts, READOUT PROTECTION
option can be deactivated only by U.V. erasure
that also results into the whole EPROM context
erasure.
Note: Once the Readout Protection is activated, it
is no longer possible, even for STMicroelectronics,
to gain access to the OTP contents. Returned
parts with a protection set can therefore not be ac-
cepted.
Figure 4. Program Memory Map
0000h
007Fh
0080h
RESERVED^*
USER
PROGRAM MEMORY
3872 BYTES
0F9Fh
0FA0h
0FEFh
0FF0h
0FF7h
0FF8h
0FFBh
0FFCh
0FFDh
0FFEh
0FFFh
RESERVED^*
INTERRUPT VECTORS
RESERVED
NMI VECTOR
USER RESET VECTOR
(*) Reserved areas should be filled with 0FFh
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