AT25BCM512B Datasheet, PDF (2/33 Pages) List of Unclassifed Manufacturers – 512-Kilobit 2.7-Volt Minimum SPI Serial Flash Memory

2. Pin Descriptions and Pinouts
Table 2-1. Pin Descriptions
Symbol Name and Function
Asserted
State
CHIP SELECT: Asserting the CS pin selects the device. When the CS pin is deasserted, the
device will be deselected and normally be placed in standby mode (not Deep Power-Down
mode), and the SO pin will be in a high-impedance state. When the device is deselected,
data will not be accepted on the SI pin.
CS
Low
A high-to-low transition on the CS pin is required to start an operation, and a low-to-high
transition is required to end an operation. When ending an internally self-timed operation
such as a program or erase cycle, the device will not enter the standby mode until the
completion of the operation.
SERIAL CLOCK: This pin is used to provide a clock to the device and is used to control the
SCK
flow of data to and from the device. Command, address, and input data present on the SI pin
is always latched in on the rising edge of SCK, while output data on the SO pin is always
-
clocked out on the falling edge of SCK.
SERIAL INPUT: The SI pin is used to shift data into the device. The SI pin is used for all data
input including command and address sequences. Data on the SI pin is always latched in on
SI
the rising edge of SCK.
-
Data present on the SI pin will be ignored whenever the device is deselected (CS is
deasserted).
SERIAL OUTPUT: The SO pin is used to shift data out from the device. Data on the SO pin
is always clocked out on the falling edge of SCK.
SO
-
The SO pin will be in a high-impedance state whenever the device is deselected (CS is
deasserted).
WRITE PROTECT: The WP pin controls the hardware locking feature of the device. Please
refer to “Protection Commands and Features” on page 11 for more details on protection
features and the WP pin.
WP
Low
The WP pin is internally pulled-high and may be left floating if hardware controlled protection
will not be used. However, it is recommended that the WP pin also be externally connected
to V_CC whenever possible.
HOLD: The HOLD pin is used to temporarily pause serial communication without
deselecting or resetting the device. While the HOLD pin is asserted, transitions on the SCK
pin and data on the SI pin will be ignored, and the SO pin will be in a high-impedance state.
The CS pin must be asserted, and the SCK pin must be in the low state in order for
a Hold condition to start. A Hold condition pauses serial communication only and
HOLD
does not have an effect on internally self-timed operations such as a program or
Low
erase cycle. Please refer to “Hold” on page 24 for additional details on the Hold
operation.
The HOLD pin is internally pulled-high and may be left floating if the Hold function will not be
used. However, it is recommended that the HOLD pin also be externally connected to V_CC
whenever possible.
DEVICE POWER SUPPLY: The V_CC pin is used to supply the source voltage to the device.
V_CC
Operations at invalid V_CC voltages may produce spurious results and should not be
-
attempted.
GND
GROUND: The ground reference for the power supply. GND should be connected to the
system ground.
-
Type
Input
Input
Input
Output
Input
Input
Power
Power
2 AT25BCM512B [Preliminary]
3704BX–DFLASH–11/2012