W25Q16DW_12 Datasheet, PDF (15/85 Pages) Winbond – 1.8V 16M-BIT SERIAL FLASH MEMORY WITH DUAL/QUAD SPI & QPI

W25Q16DW
the top 4KB sector will become unprotected while the rest of the array become read-only. Please refer to
the Status Register Memory Protection table for details. The default setting is CMP=0.
7.1.7 Status Register Protect (SRP1, SRP0)
The Status Register Protect bits (SRP1 and SRP0) are non-volatile read/write bits in the status register
(S8 and S7). The SRP bits control the method of write protection: software protection, hardware
protection, power supply lock-down or one time programmable (OTP) protection.
SRP1 SRP0 /WP
Status
Register
Description
0
0
X
Software /WP pin has no control. The Status register can be written to
Protection after a Write Enable instruction, WEL=1. [Factory Default]
0
1
0
Hardware
Protected
When /WP pin is low the Status Register locked and can not
be written to.
0
1
1
Hardware When /WP pin is high the Status register is unlocked and can
Unprotected be written to after a Write Enable instruction, WEL=1.
1
0
X
Power Supply Status Register is protected and can not be written to again
Lock-Down until the next power-down, power-up cycle.⁽¹⁾
1
1
X
One Time Status Register is permanently protected and can not be
Program⁽²⁾ written to.
Note:
1. When SRP1, SRP0 = (1, 0), a power-down, power-up cycle will change SRP1, SRP0 to (0, 0) state. 2.
This feature is available upon special order. Please contact Winbond for details.
7.1.8 Erase/Program Suspend Status (SUS)
The Suspend Status bit is a read only bit in the status register (S15) that is set to 1 after executing a
Erase/Program Suspend (75h) instruction. The SUS status bit is cleared to 0 by Erase/Program Resume
(7Ah) instruction as well as a power-down, power-up cycle.
7.1.9 Security Register Lock Bits (LB3, LB2, LB1, LB0)
The Security Register Lock Bits (LB3, LB2, LB1, LB0) are non-volatile One Time Program (OTP) bits in
Status Register (S13, S12, S11, S10) that provide the write protect control and status to the Security
Registers. The default state of LB3-0 is 0, Security Registers are unlocked. LB3-0 can be set to 1
individually using the Write Status Register instruction. LB3-0 are One Time Programmable (OTP), once
it’s set to 1, the corresponding 256-Byte Security Register will become read-only permanently.
7.1.10 Quad Enable (QE)
The Quad Enable (QE) bit is a non-volatile read/write bit in the status register (S9) that allows Quad SPI
and QPI operation. When the QE bit is set to a 0 state (factory default), the /WP pin and /HOLD are
enabled. When the QE bit is set to a 1, the Quad IO2 and IO3 pins are enabled, and /WP and /HOLD
functions are disabled.
QE bit is required to be set to a 1 before issuing an “Enable QPI (38h)” to switch the device from
Standard/Dual/Quad SPI to QPI, otherwise the command will be ignored. When the device is in QPI mode,
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Publication Release Date: September 06, 2012
Revision F