ST72344S4 datasheet(30/247 Pages) STMICROELECTRONICS

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Flash program memory

ST72344xx, ST2345xx

30/247

Doc ID 12321 Rev 6

In Flash devices, this protection is removed by reprogramming the option. In this case, both

program and data E2 memory are automatically erased, and the device can be

reprogrammed.

Read-out protection selection depends on the device type:

●

In Flash devices, it is enabled and removed through the FMP_R bit in the option byte.

●

In ROM devices, it is enabled by mask option specified in the Option List.

4.5.2

Flash write/erase protection

Write/erase protection, when set, makes it impossible to both overwrite and erase program

memory. It does not apply to E2 data. Its purpose is to provide advanced security to

applications and prevent any change being made to the memory content.

Warning:

Once set, Write/erase protection can never be removed. A

write-protected Flash device is no longer reprogrammable.

Write/erase protection is enabled through the FMP_W bit in the option byte.

4.6

4.6.1

Flash control/status register (FCSR)

Reset value: 0000 0000 (00h)

1st RASS Key: 0101 0110 (56h)

2nd RASS Key: 1010 1110 (AEh)

Note:

This register is reserved for programming using ICP, IAP or other programming methods. It

controls the XFlash programming and erasing operations. For details on XFlash

programming, refer to the ST7 Flash Programming Reference Manual.

When an EPB or another programming tool is used (in socket or ICP mode), the RASS keys

are sent automatically.

0000

OPT

LAT

PGM

Read/Write

ST72344S4 데이터시트(PDF) 30 Page - STMicroelectronics