Dell S1909WNf Service Manual page 19

8.2 U108 (Serial Flash)
Pin Symbol
1 CE#
2 SO
3 WP#
4 VSS
5 SI
6 SCK
I/O
I The device is enabled by a high to low transition on CE#.
CE#
must remain low for the duration of any command
sequence.
I/O To transfer commands, addresses, or data serially into the
device.
I/O The write protect (WP#) pin is used to enable/disable BPL
bit in
the status register.
G Connect ground
I/O To transfer commands, addresses, or data serially into the
device
input are latched on the rising edge of the serial clock.
I/O To provide the timing of serial interface.
Commands, addresses, or input data are latched on the
Description
18
Service Manual