M25P05 Datasheet, PDF (7/32 Pages) STMicroelectronics – 512 Kbit, Low Voltage, Serial Flash Memory With 20 MHz SPI Bus Interface

M25P05
Hold Condition
The Hold (HOLD) signal is used to pause any se-
rial communications with the device without reset-
ting the clocking sequence. However, taking this
signal Low does not terminate any Write Status
Register, Program or Erase cycle that is currently
in progress.
To enter the Hold condition, the device must be
selected, with Chip Select (S) Low.
The Hold condition starts on the falling edge of the
Hold (HOLD) signal, provided that this coincides
with Serial Clock (C) being Low (as shown in Fig-
ure 6).
The Hold condition ends on the rising edge of the
Hold (HOLD) signal, provided that this coincides
with Serial Clock (C) being Low.
If the falling edge does not coincide with Serial
Clock (C) being Low, the Hold condition starts
when Serial Clock (C) next goes Low. Similarly, if
the rising edge does not coincide with Serial Clock
(C) being Low, the Hold condition ends when Se-
rial Clock (C) next goes Low. (This is shown in Fig-
ure 6).
During the Hold condition, the Serial Data Output
(Q) is high impedance, and Serial Data Input (D)
and Serial Clock (C) are Don’t Care.
Normally, the device is kept selected, with Chip
Select (S) driven Low, for the whole duration of the
Hold condition. This is to ensure that the state of
the internal logic remains unchanged from the mo-
ment of entering the Hold condition.
If Chip Select (S) goes High while the device is in
the Hold condition, this has the effect of resetting
the internal logic of the device. To restart commu-
nication with the device, it is necessary to drive
Hold (HOLD) High, and then to drive Chip Select
(S) Low. This prevents the device from going back
to the Hold condition.
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