ST10F273 datasheet(36/179 Pages) STMICROELECTRONICS

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Internal Flash memory

ST10F273

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5.5

Protection strategy

The protection bits are stored in Non Volatile Flash cells, that are read once at reset and

stored in 5 Volatile registers. Before they are read from the Non Volatile cells, all the

available protections are forced active during reset.

The protections can be programmed using the Set Protection operation (see Flash Control

Registers paragraph), that can be executed from all the internal or external memories.

Two kind of protections are available: write protections to avoid unwanted writings and

access protections to avoid piracy. In next paragraphs all different level of protections are

shown, and architecture limitations are highlighted as well.

5.5.1

Protection registers

The 5 Non Volatile Protection Registers are one time programmable for the user.

Two register (FNVWPIRL/FNVWPIRH) are used to store the Write Protection fuses for each

sector IFlash module. The other three Registers (FNVAPR0 and FNVAPR1L/H) are used to

store the Access Protection fuses.

RESER

Resume error

This bit is automatically set when a suspended Program or Erase operation is not resumed

correctly due to a protocol error. In this case the suspended operation is aborted. This bit has to be

software reset.

WPF

Write protection flag

This bit is automatically set when trying to program or erase in a sector write protected. In case of

multiple Sector Erase, the not protected sectors are erased, while the protected sectors are not

erased and bit WPF is set. This bit has to be software reset.

Table 18.

Flash error register

Bit

Function

ST10F273 데이터시트(PDF) 36 Page - STMicroelectronics