Rainbow-electronics AT89C5122 Manuale Utente Scaricare il pdf (Pagina 30)

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

MOVC instruction executed from external Program Memory is disabled when fetching

code bytes from internal Program Memory

is sampled and latched on reset.

External code execution is enabled.

1 2 ... 25 26 27 28 29 30 31 32 33 34 35 ... 212 213

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