M95320-W View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'M95320-W' PDF : 48 Pages View PDF
M95320-W M95320-R M95320-DR
5
Operating features
Operating features
5.1
5.1.1
5.1.2
5.1.3
Supply voltage (VCC)
Operating supply voltage VCC
Prior to selecting the memory and issuing instructions to it, a valid and stable VCC voltage
within the specified [VCC(min), VCC(max)] range must be applied (see Operating conditions
in Section 9: DC and AC parameters). This voltage must remain stable and valid until the
end of the transmission of the instruction and, for a Write instruction, until the completion of
the internal write cycle (tW). In order to secure a stable DC supply voltage, it is
recommended to decouple the VCC line with a suitable capacitor (usually of the order of
10 nF to 100 nF) close to the VCC/VSS device pins.
Device reset
In order to prevent erroneous instruction decoding and inadvertent Write operations during
power-up, a power-on-reset (POR) circuit is included. At power-up, the device does not
respond to any instruction until VCC reaches the POR threshold voltage. This threshold is
lower than the minimum VCC operating voltage (see Operating conditions in Section 9: DC
and AC parameters).
At power-up, when VCC passes over the POR threshold, the device is reset and is in the
following state:
● in Standby Power mode,
● deselected,
● Status Register values:
– The Write Enable Latch (WEL) bit is reset to 0.
– The Write In Progress (WIP) bit is reset to 0.
– The SRWD, BP1 and BP0 bits remain unchanged (non-volatile bits).
It is important to note that the device must not be accessed until VCC reaches a valid and
stable level within the specified [VCC(min), VCC(max)] range, as defined under Operating
conditions in Section 9: DC and AC parameters.
Power-up conditions
When the power supply is turned on, VCC rises continuously from VSS to VCC. During this
time, the Chip Select (S) line is not allowed to float but should follow the VCC voltage. It is
therefore recommended to connect the S line to VCC via a suitable pull-up resistor (see
Figure 4).
In addition, the Chip Select (S) input offers a built-in safety feature, as the S input is edge-
sensitive as well as level-sensitive: after power-up, the device does not become selected
until a falling edge has first been detected on Chip Select (S). This ensures that Chip Select
(S) must have been high, prior to going low to start the first operation.
The VCC voltage has to rise continuously from 0 V up to the minimum VCC operating voltage
defined under Operating conditions in Section 9: DC and AC parameters, and the rise time
must not vary faster than 1 V/µs.
Doc ID 5711 Rev 14
13/48
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