Signal descriptions
M25PX80
2
Signal descriptions
2.1
Serial Data output (DQ1)
This output signal is used to transfer data serially out of the device. Data are shifted out on
the falling edge of Serial Clock (C).
During the Dual Input Fast Program (DIFP) instruction, pin DQ1 is used as an input. It is
latched on the rising edge of the Serial Clock (C).
2.2
Serial Data input (DQ0)
This input signal is used to transfer data serially into the device. It receives instructions,
addresses, and the data to be programmed. Values are latched on the rising edge of Serial
Clock (C).
During the Dual Output Fast Read (DOFR) instruction, pin DQ0 is used as an output. Data
are shifted out on the falling edge of the Serial Clock (C).
2.3
2.4
Serial Clock (C)
This input signal provides the timing of the serial interface. Instructions, addresses, or data
present at Serial Data input (DQ0) are latched on the rising edge of Serial Clock (C). Data
on Serial Data output (DQ1) changes after the falling edge of Serial Clock (C).
Chip Select (S)
When this input signal is High, the device is deselected and Serial Data output (DQ1) is at
high impedance. Unless an internal Program, Erase or Write Status Register cycle is in
progress, the device will be in the Standby Power mode (this is not the Deep Power-down
mode). Driving Chip Select (S) Low enables the device, placing it in the Active Power mode.
After power-up, a falling edge on Chip Select (S) is required prior to the start of any
instruction.
2.5
Hold (HOLD)
The Hold (HOLD) signal is used to pause any serial communications with the device without
deselecting the device.
During the Hold condition, the Serial Data output (DQ1) is high impedance, and Serial Data
input (DQ0) and Serial Clock (C) are Don’t care.
To start the Hold condition, the device must be selected, with Chip Select (S) driven Low.
2.6
Write Protect/Enhanced Program supply voltage (W/VPP)
W/VPP is both a control input and a power supply pin. The two functions are selected by the
voltage range applied to the pin.
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