Rainbow Electronics AT89C5122 - Manual (Page 30)

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AT8xC5122/23
4202E–SCR–06/06
AT8xC5122’s ROM
Version The AT8xC5122’s ROM version implements :
- 32 K of ROM mapped from 0000h to 7FFFh in which is embedded the user code. The
ROM device is only factory programmable.
- 512 bytes of E2PROM can be optionally implemented to store permanent data. With
this option, the size of ROM is reduced to 30K.
After the reset, the MCU begins the execution of the user code from location 0000h of
the ROM.
Access to external Program Memory is not allowed.
Security Level There are two security levels (applicable to High Pin Count packages only) :
The security level 2 can be used to protect the user code from piracy. This option is con-
figured at factory and must be requested by the customer at order time.
Table 9. Security Levels Description
Security Level Protection description
1 No protection lock enabled
2
MOVC instruction executed from external Program Memory is disabled when fetching
code bytes from internal Program Memory
EA is sampled and latched on reset.
External code execution is enabled.