Hard Lock Protection - Samsung S3F84B8 User Manual

S3F84B8_UM_REV 1.00

19.1.9 HARD LOCK PROTECTION

You can set Hard Lock Protection by writing '0110B' in FMCON7–4. This function prevents data change in flash
memory area. If this function is enabled, you cannot write or erase data in flash memory anymore. This protection
can be released by chip erase in Tool Program mode. To set Hard Lock Protection in Tool mode, refer to the
"Serial Program Writer Tool Manual".
Program Procedure in User Program Mode
To set Hard Lock Protection in User Program mode, follow these steps:
1. Set Flash Memory User Programming Enable Register (FMUSR) to "10100101B".
2. Set Flash Memory Control Register (FMCON) to "01100001B".
3. Set Flash Memory User Programming Enable Register (FMUSR) to "00000000B".
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SB1
LD FMUSR,#0A5H
LD FMCON,#01100001B
LD FMUSR,#00H
SB0
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Example 19-4 Hard Lock Protection
; Enables User Program mode
; Selects Hard Lock mode and starts protection
; Disables User Program mode
19-15
19 EMBEDDED FLASH MEMORY INTERFACE