1. Memory Protection & Status Register Bits


️· WIP (Write In Progress): Indicates if the memory is busy (Program/Erase/Write Status Register in progress). 1=Busy, 0=Idle.
️· WEL (Write Enable Latch): Controls write access. 1=Enabled, 0=Disabled.
️· BP4-BP0 (Block Protect): Non-volatile bits that define the size of the protected memory area. Default: 0 (no protection). They, when set, prevent Page Program, Sector Erase and Block Erase commands.
️· SRP1, SRP0 (Status Register Protect): Control how the Status Register itself can be written. They define if the access to the Status Register is controlled by software, hardware, Power Supply Lock-Down or One-Time Programmable.
- See the table on the document for details about the relation of SRP1, SRP0, WP# pin and Status Register access.
️· QE (Quad Enable): Enables Quad mode operation. Default: 0 (standard SPI/Dual SPI). When set, IO2/IO3 pins are enabled.
️· HPF (High Performance Flag): Indicates if the device is in High Performance Mode. 1=In HPF mode, 0 = Not in HPF mode.
️· LB3-LB1: Non-volatile One Time Programmable (OTP) bits that provide control to the Security Registers. When set to 1, the Security Registers become read-only.
️· CMP (Compare): Non-volatile Read/Write bit that, with BP4-BP0, provides more array protection flexibility. Default: 0.
️· SUS (Suspend): Read-only bit, set by Erase/Program Suspend command. Cleared by Erase/Program Resume or power cycle.

2. Status Register Protection Modes (SRP)

SRP1	SRP0	WP#	Status Register	Description
0	0	X	Software Protected	Status Register is written after a Write Enable command, WEL=1
0	1	0	Hardware Protected	Status Register is locked when WP# is low
0	1	1	Hardware Unprotected	Status Register is written after WEL=1 when WP# is high
1	0	X	Power Supply Lock-Down	Status Register is permanently protected after a Power-Down, Power-Up cycle
1	1	X	One-Time Program	Status Register is permanently protected; cannot be written again

3. Important Considerations & Notes:

️· One-Time Programmable (OTP): LB3-LB1 and SRP1/SRP0 (in certain modes) are OTP, meaning they can only be written once.
️· Default Values: Be aware of the default values of the status register bits (e.g., WEL=0, QE=0, CMP=0).
️· WP# Pin: The Write Protect # pin significantly influences the status register protection based on the SRP settings.
️· Quad Mode & WP#/HOLD#: When using Quad mode (QE=1), be mindful of the WP# and HOLD# pins, as their function is altered.