m95256-dr STMicroelectronics, m95256-dr Datasheet - Page 10

• Manufacturer Part Number: m95256-dr
• Description: 256 Kbit Serial Spi Bus Eeprom With High-speed Clock
• Manufacturer: STMicroelectronics

Signal description
3.6
3.7
3.8
3.8.1
3.8.2
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Write Protect (W)
The main purpose of this input signal is to freeze the size of the area of memory that is
protected against Write instructions (as specified by the values in the BP1 and BP0 bits of
the Status Register).
This pin must be driven either high or low, and must be stable during all write instructions.
V
V
Operating supply voltage (V
Prior to selecting the memory and issuing instructions to it, a valid and stable V
within the specified [V
Table
This voltage must remain stable and valid until the end of the transmission of the
instructionand, for a Write instruction, until the completion of the internal write cycle (t
with a suitable capacitor (usually of the order of 10 nF to 100 nF) close to the V
package pins.
Device reset
In order to prevent 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 V
reaches the internal Reset threshold voltage (this threshold is defined in DC tables as
V
Table 9
When V
●
●
●
When V
Power mode, however, the device must not be accessed until V
stable V
and
Power-up conditions
When the power supply is turned on, V
time, the Chip Select (S) line is not allowed to float but should follow the V
In order to secure a stable DC supply voltage, it is recommended to decouple the VCC line
SS
RES
SS
Table
is the reference for the V
in Standby Power mode,
deselected (note that a further instruction must be preceded by a falling edge on Chip
Select (S) to be executed),
Status Register value:
–
–
–
). (this threshold is lower than the minimum V
10).
ground
and
CC
CC
CC
the Write Enable Latch (WEL) is reset to 0,
Write In Progress (WIP) is reset to 0,
The SRWD, BP1 and BP0 bits remain unchanged (non-volatile bits)
10).
voltage within the specified [V
passes over the POR threshold, the device is reset and in the following state:
passes over the POR threshold, the device is reset and enters the Standby
Table
10).
CC(min)
, V
CC
Doc ID 12276 Rev 11
CC(max)
supply voltage.
] range must be applied (see
CC
CC(min)
CC
rises continuously from V
)
M95256-DR, M95256, M95256-W, M95256-R
, V
CC(max)
CC
operating voltage defined in
] range defined in
CC
reaches a valid and
SS
Table
to V
CC
8,
CC
Table
Table
voltage, it is
. During this
CC
CC
8,
/V
Table
voltage
9,
SS
Table 9
CC
W
).
8,