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W25Q16CV
Publication Release Date: April 01, 2011
- 15 -
Revision C
CMP is set to 1, previous array protection set by SEC, TB, BP2, BP1 and BP0 will be reversed. For
instance, when CMP=0, a top 4KB sector can be protected while the rest of the array is not; when CMP=1,
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 Bits (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
X
Software
Protection
/WP pin has no control. The Status register can be written to
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
Hardware
Unprotected
When /WP pin is high the Status register is unlocked and can
be written to after a Write Enable instruction, WEL=1.
1
0
X
Power Supply
Lock-Down
Status Register is protected and can not be written to again
until the next power-down, power-up cycle.
(1)
1
X
One Time
Program
(2)
Status Register is permanently protected and can not be
written to.
Notes:
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)
The Security Register Lock Bits (LB3, LB2, LB1) are non-volatile One Time Program (OTP) bits in Status
Register (S13, S12, S11) that provide the write protect control and status to the Security Registers. The
default state of LB[3:1] is 0, Security Registers are unlocked. LB[3:1] can be set to 1 individually using the
Write Status Register instruction. LB[3:1] 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 Bit (QE)
The Quad Enable (QE) bit is a non-volatile read/write bit in the status register (S9) that allows Quad SPI
operation. When the QE bit is set to a 0 state (factory default), the /WP pin and /HOLD are enabled. When