8.1 Package Types
8-pin plastic 150-mil width SOIC, 8-pin plastic 208-mil width SOIC, 6x5-mm WSON, 8-pin PDIP
and 16-pin plastic 300-mil width SOIC as shown in figure 1a, 1b,1c and 1d respectively.
Package diagrams and dimensions are illustrated at the end of this datasheet.
8.2 Chip Select (/CS)
The SPI Chip Select (/CS) pin enables and disables device operation. When /CS is high the device
is deselected and the Serial Data Output (DO, or IO0, IO1, IO2, IO3) pins are at high impedance.
When deselected, the device power consumption will be at standby levels unless an internal erase,
program or write status register cycle is in progress. When /CS is brought low the device will be
selected, power consumption will increase to active levels and instructions can be written to and
read data from the device. After power-up, /CS must transition from high to low before a new
instruction will be accepted. The /CS input must track the VCC supply level at power-up (see “Write
Protection” and figure 31). If needed a pull-up resister on /CS can be used to accomplish this.
8.3 Serial Data Input, Output and IOs (DI, DO and IO0, IO1, IO2, IO3)
The FM25Q32 supports standard SPI, Dual SPI and Quad SPI operation. Standard SPI
instructions use the unidirectional DI (input) pin to serially write instructions, addresses or data to
the device on the rising edge of the Serial Clock (CLK) input pin. Standard SPI also uses the
unidirectional DO (output) to read data or status from the device on the falling edge of CLK.
Dual and Quad SPI instructions use the bidirectional IO pins to serially write instructions,
addresses or data to the device on the rising edge of CLK and read data or status from the device
on the falling edge of CLK. Quad SPI instructions require the non-volatile Quad Enable bit (QE) in
Status Register-2 to be set. When QE=1 the /WP pin becomes IO2 and /HOLD pin becomes IO3.
8.4 Write Protect (/WP)
The Write Protect (/WP) pin can be used to prevent the Status Register from being written. Used in
conjunction with the Status Register’s Block Protect (SEC. TB. BP2, Bp1 and BP0) bits and Status
Register Protect (SRP) bits, a portion or the entire memory array can be hardware protected. The
/WP pin is active low. When the QE bit of Status Register-2 is set for Quad I/O, the /WP pin
(Hardware Write Protect) function is not available since this pin is used for IO2. See figure 1a, 1b,
1c and 1d for the pin configuration of Quad I/O operation.
8.5 HOLD (/HOLD)
The /HOLD pin allows the device to be paused while it is actively selected. When /HOLD is brought
low, while /CS is low, the DO pin will be at high impedance and signals on the DI and CLK pins will
be ignored (don’t care). When /HOLD is brought high, device operation can resume. The /HOLD
function can be useful when multiple devices are sharing the same SPI signals. The /HOLD pin is
active low. When the QE bit of Status Register-2 is set Quad I/O, the /HOLD pin function is not
available since this pin used for IO3. See figure 1a, 1b, 1c and 1d for the pin configuration of Quad
8.6 Serial Clock (CLK)
The SPI Serial Clock Input (CLK) pin provides the timing for serial input and output operations.
(“See SPI Operations”)