SLVSHO1A March 2025 – December 2025 TPS1689
PRODUCTION DATA
MFR_WRITE_PROTECT is a manufacturer specific command used to lock or unlock access to the configuration registers, NVM and EEPROM to prevent accidental/spurious PMBus® writes from altering the device configuration. It also blocks access to the OPERATION, RESTORE_FACTORY_DEFAULTS, STORE_USER_ALL, RESTORE_USER_ALL, BB_ERASE, and POWER_CYCLE commands to prevent accidental/spurious PMBus® writes from altering the device state. The device is locked by default after power up or enable recycling.
This command uses the PMBus® read or write byte protocol.
A valid unlock command contains a data byte with Bit[7] equal to one (1) followed by a 7-bit password that matches a predefined pattern of 0x0100010. Writing 0xA2h in the MFR_WRITE_PROTECT register unlocks the device. Writing 0x00h in the MFR_WRITE_PROTECT register locks the device.
Writing a data byte other than 0xA2h or 0x00h in the MFR_WRITE_PROTECT register will not change the lock status of the device, but will generate a CML error and set the INV_DATA bit in STATUS_CML register.
If the WP# pin is pulled low, the write access is completely disabled in hardware and MFR_WRITE_PROTECT command has no effect.
| Bit | Name | Value | Description | Default | Access |
|---|---|---|---|---|---|
7 | UNLOCK | Lock Bit | Read/Write | ||
0 | Configuration register/NVM space locked | 0 | |||
1 | Configuration register/NVM space unlocked | ||||
6:0 | PWD | Password | |||
0000000 | Configuration register/NVM space locked | 0000000 | |||
| 0100010 | Configuration register/NVM space unlocked | ||||
0000011 | Configuration register/NVM space locked until Power-On Reset |