Rainbow Electronics AT25DL161 - Manual (Page 3)

3 AT25DL161 [DATASHEET]
8795E–DFLASH–12/2012
2. Pin Descriptions and Pinouts
Table 2-1. Pin Descriptions
Symbol Name and Function
Asserted
State Type
CS
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.
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.
Low Input
SCK
Serial Clock: This pin is used to provide a clock to the device and is used to
control the 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.
— Input
SI (SIO)
Serial Input (Serial Input/Output): 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 the rising edge of SCK.
With the Dual-Output Read Array command, the SI pin becomes an output pin
(SIO) to allow two bits (on the SO and SIO pins) of data to be clocked out on
every falling edge of SCK. To maintain consistency with SPI nomenclature, the
SIO pin will be referenced as SI throughout this document except for those
sections dealing with the Dual-Output Read Array command, in which it will be
referenced as SIO.
Data present on the SI pin will be ignored whenever the device is deselected
(CS is deasserted).
— Input/Output
SO (SOI)
Serial Output (Serial Output/Input): 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.
With the Dual-Input Byte/Page Program command, the SO pin becomes an
input pin (SOI) to allow two bits (on the SOI and SI pins) of data to be clocked in
on every rising edge of SCK. To maintain consistency with nomenclature, the
SOI pin will be referenced as SO throughout this document except for those
sections dealing with the Dual-Input Byte/Page Program command in which it
will be referenced as SOI.
The SO pin will be in a high-impedance state whenever the device is deselected
(CS is deasserted).
— Input/Output
WP
Write Protect: The WP pin controls the hardware locking feature of the device.
See “Protection Commands and Features” on page 21 for more details on
protection features and the WP pin.
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.
Low Input