Flash Security Bit Command

A security bit can be set using the Set Security Bit command (SSE). Once the security bit is active, the Fast Flash programming is disabled. No other command can be run. An event on the Erase signal can erase the security bit once the contents of the Flash have been erased.

Table 1. Set Security Bit Command
Step Handshake Sequence MODE[3:0] DATA[15:0]
1 Write handshaking CMDE SSE
2 Write handshaking DATA 0

Once the security bit is set, it is not possible to access FFPI. The only way to erase the security bit is to erase the Flash.

To erase the Flash, perform the following steps:

  1. 1.Power off the chip.
  2. 2.Power on the chip with TST = 0.
  3. 3.Assert the ERASE signal for at least the ERASE pin assertion time as defined in the section “Electrical Characteristics”.
  4. 4.Power off the chip.

Return to FFPI mode to check that the Flash is erased.

Parent topic: Device Operations