LE25FW808 Datasheet, PDF (6/27 Pages) Sanyo Semicon Device – 8M-bit (1024K×8) Serial Flash Memory with High-Density Read Mode

LE25FW808
Outline of High-Density read mode (HD_READ mode) operation
LE25FW808 has the HD_READ mode in addition to two kinds of normal read (4 bus read and 5 bus read). The
HD_READ mode is greatly different from the normal mode in three points.
The first is the difference of the role of pins. Four pins (SO, WP, HOLD, SI) become I/O pins (SIO3 to SIO0) in the
HD_READ mode while the input pin (SI) and the output pin (SO) are only one in the normal mode respectively as
shown in Figure 2. Because SO, WP, HOLD and SI operate as I/O pin in the HD_READ mode, the setting of read
address and the outputting read data become to be done from four pins.
The second is the difference of the relation between the clock and the data output. The rising edge of SCK is made a
trigger for the address input and the falling edge of SCK is made a trigger for the data output in the normal mode.
However, both edges of rising and falling of SCK will be done to the address taking and the data outputting in the
HD_READ mode.
The third is the difference of the data composition at the time of reading. It is read by the ×16 bit in the HD_READ
mode though it is read by the ×8 bit in the normal read. Therefore, please fix least significant bit (LSB) : A0 to L in the
address input in HD_READ mode.
Pin Assignments
CS
SO
WP
VSS
1
8
VDD
2
7
HOLD
3
6
SCK
4
5
SI
Normal mode Top view
Entry
Slipping out
CS
SIO3
SIO2
VSS
1
8
VDD
2
7
SIO1
3
6
SCK
4
5
SIO0
HD_READ mode
Top view
Figure 5: Serial input / output timing diagram for HD_READ mode (CL=1.0)
tCSS
tCLHI tCLLO
tCLZ
CS
tAS tAH tAS tAH tAS tAH
tV2
tHO
SCK
SIO3
“0”
SIO2
A22
SIO1
A21
SIO0
A20
A3
data
data
A2
data
data
A1
data
data
“0”
data
data
No.A0839-6/27