W25P10, W25P20 AND W25P40

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the VCC supply level at power-up (see “Write Protection” and figure 16). If needed a pull-up resister

on /CS can be used to accomplish this.

4.3

Serial Data Output (DO)

The SPI Serial Data Output (DO) pin provides a means for data and status to be serially read from

(shifted out of) the device. Data is shifted out on the falling edge of the Serial Clock (CLK) input pin.

4.4

Write Protect (/WP)

The Write Protect (/WP) pin can be used to prevent the Status Register from being written. Used in

conjunction with the Status Register’s Block Protect (BP2, BP1, and BP0) bits and Status Register

Protect (SRP) bits, a portion or the entire memory array can be hardware protected. The /WP pin is

active low.

4.5

HOLD (/HOLD)

The /HOLD pin allows the device to be paused while it is actively selected. When /HOLD is brought

low, while /CS is low, the DO pin will be at high impedance and signals on the DI and CLK pins will be

ignored (don’t care). When /HOLD is brought high, device operation can resume. The /HOLD function

can be useful when multiple devices are sharing the same SPI signals. (“See Hold function”)

4.6

Serial Clock (CLK)

The SPI Serial Clock Input (CLK) pin provides the timing for serial input and output operations. ("See

SPI "Operations")

4.7

Serial Data Input (DI)

The SPI Serial Data Input (DI) pin provides a means for instructions, addresses and data to be serially

written to (shifted into) the device. Data is latched on the rising edge of the Serial Clock (CLK) input

pin.