MX25L1635DMI-12G 参数 Datasheet PDF下载

MX25L1635D

(4) Read Status Register (RDSR)

The RDSR instruction is for reading Status Register Bits. The Read Status Register can be read at any time (even in

program/erase/write status register condition) and continuously. It is recommended to check the Write in Progress (WIP)

bit before sending a new instruction when a program, erase, or write status register operation is in progress.

The sequence of issuing RDSR instruction is: CS# goes low-> sending RDSR instruction code-> Status Register data out

on SO (see Figure 12)

The definition of the status register bits is as below:

WIP bit.

The Write in Progress (WIP) bit, a volatile bit, indicates whether the device is busy in program/erase/write status

register progress. When WIP bit sets to 1, which means the device is busy in program/erase/write status register progress.

When WIP bit sets to 0, which means the device is not in progress of program/erase/write status register cycle.

WEL bit.

The Write Enable Latch (WEL) bit, a volatile bit, indicates whether the device is set to internal write enable latch.

When WEL bit sets to 1, which means the internal write enable latch is set, the device can accept program/erase/write

status register instruction. When WEL bit sets to 0, which means no internal write enable latch; the device will not accept

program/erase/write status register instruction. The program/erase command will be ignored and not affect value of WEL

bit if it is applied to a protected memory area.

BP3, BP2, BP1, BP0 bits.

The Block Protect (BP3, BP2, BP1, BP0) bits, non-volatile bits, indicate the protected area(as

defined in table 1) of the device to against the program/erase instruction without hardware protection mode being set. To

write the Block Protect (BP3, BP2, BP1, BP0) bits requires the Write Status Register (WRSR) instruction to be executed.

Those bits define the protected area of the memory to against Page Program (PP), Sector Erase (SE), Block Erase (BE)

and Chip Erase(CE) instructions (only if all Block Protect bits set to 0, the CE instruction can be executed).

QE bit.

The Quad Enable (QE) bit, non-volatile bit, performs Quad when it is reset to "0" (factory default) to enable WP#

or is set to "1" to enable Quad SIO2 and SIO3.

SRWD bit.

The Status Register Write Disable (SRWD) bit, non-volatile bit, which is set to "0" (factory default). The SRWD

bit is operated together with Write Protection (WP#/SIO2) pin for providing hardware protection mode. The hardware

protection mode requires SRWD sets to 1 and WP#/SIO2 pin signal is low stage. In the hardware protection mode, the

Write Status Register (WRSR) instruction is no longer accepted for execution and the SRWD bit and Block Protect bits

(BP3, BP2, BP1, BP0) are read only.

Status Register

bit7

bit6

bit5

bit4

bit3

bit2

bit1

bit0

BP3

SRWD

BP2

BP1

BP0

WEL

WIP

QE

(level of

(status register (Quad Enable)

(level of

(level of

(level of

(write enable

(write in

write protect)

latch)

protected block) protected block) protected block) protected block)

progress bit)

1= write

1= Quad

Enable

1= status

operation

1= write enable

(note1)

(note1)

(note1)

(note1)

register write

0=not Quad

0= not write 0= not in write

Enable

disable

operation

enable

Non- volatile bit Non- volatile bit Non- volatile bit Non- volatile bit Non- volatile bit Non- volatile bit volatile bit

volatile bit

Note 1: see the table 2 "Protected Area Size" in page 11.

P/N: PM1374

16

REV. 1.5, OCT. 01, 2008