M95080-DRDW4TG datasheet(16/42 Pages) STMICROELECTRONICS

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Instructions

M95080-A125 M95080-A145

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DocID024205 Rev 8

4.1

Write Enable (WREN)

The WREN instruction must be decoded by the device before a write instruction (WRITE,

WRSR, WRID or LID).

As shown in Figure 5, to send this instruction to the device, Chip Select (S) is driven low, the

bits of the instruction byte are shifted in (MSB first) on Serial Data Input (D) after what the

Chip Select (S) input is driven high and the WEL bit is set (Status Register bit).

Figure 5. Write Enable (WREN) sequence

4.2

Write Disable (WRDI)

One way of resetting the WEL bit (in the Status Register) is to send a Write Disable

instruction to the device.

As shown in Figure 6, to send this instruction to the device, Chip Select (S) is driven low,

and the bits of the instruction byte are shifted in (MSB first), on Serial Data Input (D), after

what the Chip Select (S) input is driven high and the WEL bit is reset (Status Register bit).

If a Write cycle is currently in progress, the WRDI instruction is decoded and executed and

the WEL bit is reset to 0 with no effect on the ongoing Write cycle.

Figure 6. Write Disable (WRDI) sequence

M95080-DRDW4TG Datasheet(PDF) 16 Page - STMicroelectronics