M95P16-IXCSSLASHEF datasheet(26/63 Pages) STMICROELECTRONICS

26 / 63 page

6.8

Write Status and Configuration registers (01h)

The Write Status register (WRSR) instruction is used to write the Status and Configuration registers.

A WRSR instruction, used with one data byte, changes Status register bits SRWD, TB, BPx and WEL.

A WRSR instruction, used with two data bytes, can change Status register bits, configuration bits (DVx), and Lock

ID bit (LID), located in the Configuration register.

To write the Status and Configuration registers, a Write enable (06h) instruction must have been previously

executed (Status register bit WEL must be 1). Once write is enabled, the Write Status register (WRSR) instruction

is entered (MSB first) by driving S low, sending the instruction code 01h, followed by one or two data byte(s) on

Serial data input (D), and driving the S high.

The S pin must be driven high after the eighth bit has been latched. If this is not done the instruction is not

executed.

The bytes of the Status and Configuration registers are stored in different pages, to avoid losing the second byte

if, after having changed the first one, a power-down occurs.

A WRSR instruction with more data bytes than defined above is discarded.

The instruction is not accepted, and is not executed, if a Write cycle is in progress.

The content of the Status and Configuration registers is described in Section 5.1 Status register and

Section 5.2.1 Configuration register.

Figure 14. Write Status register

-3

-2

-1

High impedance

WRSR instruction

Status register data byte in

MS55406V1

Figure 15. Write Status and Configuration registers

High impedance

WRSR instruction

Status register data byte in

Configuration register data byte in

MS69276V1

M95P16-I M95P16-E

Write Status and Configuration registers (01h)

DS13710 - Rev 1

page 26/63

M95P16-IXCS/EF Datasheet(PDF) 26 Page - STMicroelectronics