X25F064/032/016/008
PIN DESCRIPTIONS
Serial Output (SO)
Hold (HOLD)
HOLD isusedinconjunctionwiththeCSpintoselectthe
device. Once the part is selected and a serial sequence
is underway, HOLD may be used to pause the serial
communication with the controller without resetting the
serial sequence. To pause, HOLD must be brought
LOW while SCK is LOW. To resume communication,
HOLD is brought HIGH, again while SCK is LOW. If the
pause feature is not used, HOLD should be held HIGH
at all times.
SO is a push-pull serial data output pin. During a read
cycle, data is shifted out on this pin. Data is clocked out
by the falling edge of the serial clock.
Serial Input (SI)
SI is the serial data input pin. All opcodes, byte
addresses, and data to be written to the memory are
input on this pin. Data is latched by the rising edge of the
serial clock.
PIN CONFIGURATION
Serial Clock (SCK)
The Serial Clock controls the serial bus timing for data
input and output. Opcodes, addresses, or data present
on the SI pin are latched on the rising edge of the clock
input, while data on the SO pin change after the falling
edge of the clock input.
8-Lead DIP/SOIC
CS
SO
PP
1
2
3
4
8
7
6
5
V
CC
X25F064/
032/016/
008
HOLD
SCK
SI
V
SS
Chip Select (CS)
14-Lead TSSOP
20-Lead TSSOP
When CS is HIGH, the X25F064/032/016/008 is
deselected and the SO output pin is at high impedance
and unless an internal program operation is underway
the X25F064/032/016/008 will be in the standby power
mode. CS LOW enables the X25F064/032/016/008,
placing it in the active power mode. It should be noted
that after power-up, a HIGH to LOW transition on CS is
required prior to the start of any operation.
CS
SO
NC
NC
NC
PP
NC
1
2
3
4
5
6
7
1
2
3
4
5
6
7
8
9
10
14
13
12
11
10
9
20
19
18
17
16
15
14
13
12
11
V
NC
V
CC
CS
NC
SO
NC
NC
PP
HOLD
NC
CC
NC
X25F032/
016/008
NC
HOLD
NC
NC
X25F064
SCK
SI
NC
V
8
SCK
SI
SS
V
SS
NC
NC
NC
NC
Program Protect (PP)
6685 ILL F02.4
When PP is LOW and the nonvolatile bit PPEN is “1”,
nonvolatile programming of the X25F064/032/016/008
status register is disabled, but the part otherwise func-
tions normally. When PP is held HIGH, all functions,
including nonvolatile programming operate normally.
PP going LOW while CS is still LOW will interrupt
programmingoftheX25F064/032/016/008statusregis-
ter. If the internal program cycle has already been
initiated, PP going LOW will have no effect on program-
ming.
PIN NAMES
SYMBOL
DESCRIPTION
CS
Chip Select Input
Serial Output
SO
SI
Serial Input
SCK
PP
VSS
VCC
HOLD
NC
Serial Clock Input
The PP pin function is blocked when the PPEN bit in
thestatusregisteris“0”.Thisallowstheusertoinstallthe
X25F064/032/016/008 into a system with PP pin
groundedandstillbeabletoprogramthestatusregister.
The PP pin functions will be enabled when the PPEN bit
is set “0”.
Program Protect Input
Ground
Supply Voltage
Hold Input
No Connect
6685 PGM T01.1
2
XICOR [ XICOR INC. ]
