ST62T45B STMicroelectronics, ST62T45B Datasheet - Page 9

• Manufacturer Part Number: ST62T45B
• Description: 8-BIT OTP/EPROM MCU
• Manufacturer: STMicroelectronics

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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).
1.3.2.1 Program Memory Protection
The Program Memory in OTP or EPROM devices
can be protected against external readout of
memory by selecting the READOUT PROTEC-
TION option in the option byte.
In the EPROM parts, READOUT PROTECTION
option can be disactivated 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 SGS-THOMSON,
to gain access to the Program memory contents.
Returned parts with a protection set can therefore
not be accepted.
Figure 4. ST62E45B/T45B Program
(*) Reserved areas should be filled with 0FFh
0FEFh
0FFBh
0FFCh
0FFDh
0FFEh
007Fh
0F9Fh
0FA0h
0FF0h
0FF7h
0FF8h
0FFFh
0080h
0000h
Memory Map
INTERRUPT VECTORS
USER RESET VECTOR
PROGRAM MEMORY
(OTP/EPROM)
NMI VECTOR
3872 BYTES
RESERVED
RESERVED
RESERVED
USER
ST62T45B/E45B
*
*
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