Pin Configuration
A0–A19 = 20 addresses
DQ0–DQ14 = 15 data inputs/outputs
DQ15/A-1 = DQ15 (data input/output, word mode)
A-1 (LSB address input, byte mode)
BYTE# = Selects 8-bit or 16-bit mode
CE# = Chip enable
OE# = Output enable
WE# = Write enable
RESET# = Hardware reset pin
RY/BY# = Ready/Busy output
VCC = 3.0 volt-only single power supply
VSS = Device ground
NC = Pin not connected internally
Word/Byte Configuration
BYTE#=1, the device is in word configuration, DQ15–DQ0 are active and controlled by CE# and OE#.
BYTE#=0, the device is in byte configuration, DQ0–DQ7 are active and controlled
by CE# and OE#. The data I/O pins DQ8–DQ14 are tri-stated, and the DQ15 pin is used as an input for the LSB (A-1) address function.
Reading Array Data
To read array data from the outputs, CE# =VIL,OE#=VIL,WE#=VIH.(logic low/high)
CE# is the power control and selects the device.
OE# is the output control and gates array data to the output pins.
tRC Read Cycle Time
tACC Address to Output Delay
tCE Chip Enable to Output Delay
tOE Output Enable to Output Delay
tDF Chip Enable to Output High Z
Output Enable to Output High Z 1
OEH Output Enable Hold Time
tOH Output Hold Time From Addresses,(CE# or OE# Whichever Occurs First）
Writing Commands/Command Sequences
To write a command or command sequence (which includes programming data
to the device and erasing sectors of memory).
the system must drive WE#= VIL,CE#=VIL,OE#=VIH.
Command Definitions
legend:
x=don't care
RA=Address of the memory location to be read
RD=Data read from location RA during read opeartion
PA=Address of the memory location to be programmed. Address latch on the falling edge of the WE# or CE# pulse,whichever happens later.
PD=Data to be programmed at location PA,Data latches on the rising edge of WE# or CE# pluse,whichever happens first.
SA=Address of the sector to be verified(in autoselect mode)or erased.Address bits A19-A12 uniquely select any sector.
Reading Array Data
The device is automatically set to reading array data after device power-up. No commands are required to retrieve data. The device is also ready to read array data after completing an Embedded Program or mbedded Erase algorithm.
Reset Command
Writing the reset command to the device resets the device to reading array data. Address bits are don’t care for this command.
The reset command may be written between the sequence cycles in an erase command sequence before erasing begins. This resets the device to reading array data. Once erasure begins, however, the device ignores reset commands until the operation is complete.
The reset command may be written between the sequence cycles in a program command sequence before programming begins. This resets the device to reading array data
(also applies to programming in Erase Suspend mode).nce programming begins, however, the device ignores reset commands until the operation is complete.
Autoselect Command Sequence
The autoselect command sequence allows the host system to access the manufacturer and devices codes, and determine whether or not a sector is protected.
Word/Byte Program Command Sequence
Programming is a four-bus-cycle operation. The program com
mand sequence is initiated by writing two unlock write cycles, followed by the
program set-up command. The program address and data are written next, which
in turn initiate the Embedded Program algorithm. The system is not required to
provide further controls or timings. The device automatically generates the pro
gram pulses and verifies the programmed cell margin.
