M27W032-100M1 STMicroelectronics, M27W032-100M1 Datasheet - Page 8

• Manufacturer Part Number: M27W032-100M1
• Manufacturer: STMicroelectronics

Specifications of M27W032-100M1

• Density: 32Mb
• Organization: 2Mx16
• Interface Type: Parallel
• Bus Type: Parallel
• In System Programmable: External
• Access Time (max): 100ns
• Package Type: SO
• Reprogramming Technique: OTP
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 3.6V
• Supply Current: 10mA
• Pin Count: 44
• Mounting: Surface Mount
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Supplier Unconfirmed

M27W032
COMMAND INTERFACE
All Bus Write operations to the memory are inter-
preted by the Command Interface. Commands
consist of one or more sequential Bus Write oper-
ations. Failure to observe a valid sequence of Bus
Write operations will result in the memory return-
ing to Read mode. The long command sequences
are imposed to maximize data security.
Refer to Tables 3 and 4, for a summary of the com-
mands.
Read/Reset Command.
The Read/Reset command returns the memory to
its Read mode where it behaves like a ROM or
EPROM, unless otherwise stated. It also resets
the errors in the Status Register. Either one or
three Bus Write operations can be used to issue
the Read/Reset command.
V
command. If V
mand will be ignored. The command can be is-
sued, between Bus Write cycles before the start of
a program operation, to return the device to read
mode. Once the program operation has started the
Read/Reset command is no longer accepted.
Auto Select Command.
The Auto Select command is used to read the
Manufacturer Code and the Device Code. V
must be set to V
mand. If V
mand will be ignored. Three consecutive Bus
Write operations are required to issue the Auto Se-
lect command. Once the Auto Select command is
issued the memory remains in Auto Select mode
until a Read/Reset command is issued, all other
commands are ignored.
From the Auto Select mode the Manufacturer
Code can be read using a Bus Read operation
with A0 = V
may be set to either V
The Device Code can be read using a Bus Read
operation with A0 = V
address bits may be set to either V
Word Program Command.
The Word Program command can be used to pro-
gram a Word to the memory array. V
set to V
ther V
data will remain unchanged and the device will re-
vert to Read/Reset mode. The command requires
four Bus Write operations, the final write operation
latches the address and data in the internal state
machine and starts the PC.
During the program operation the memory will ig-
nore all commands. It is not possible to issue any
command to abort or pause the operation. Typical
program times are given in Table 5. Bus Read op-
8/23
PP
must be set to V
IL
HH
or V
during Word Program. If V
PP
IL
IH
and A1 = V
is set to either V
PP
the command will be ignored, the
is set to either V
HH
during the Auto Select com-
IL
IH
HH
or V
IL
and A1 = V
. The other address bits
during the Read/Reset
IH
.
IL
IL
or V
or V
IL
PP
IL
or V
IH
PP
. The other
IH
is set to ei-
the com-
the com-
IH
must be
.
PP
erations during the program operation will output
the Status Register on the Data Inputs/Outputs.
See the section on the Status Register for more
details.
After the program operation has completed the
memory will return to the Read mode, unless an
error has occurred. When an error occurs the
memory will continue to output the Status Regis-
ter. A Read/Reset command must be issued to re-
set the error condition and return to Read mode.
Note that the Program command cannot change a
bit set at ’0’ back to ’1’.
Multiple Word Program Command
The Multiple Word Program command can be
used to program large streams of data. It greatly
reduces the total programming time when a large
number of Words are written in the memory at
once. V
Program. If V
mand will be ignored, the data will remain un-
changed and the device will revert to Read mode.
It has four phases: the Setup Phase to initiate the
command, the Program Phase to program the
data to the memory, the Verify Phase to check that
the data has been correctly programmed and re-
program if necessary and the Exit Phase.
Setup Phase. The Multiple Word Program com-
mand requires three Bus Write operations to ini-
tiate the command (refer to Table 4, Multiple Word
Program Command and Figure 8, Multiple Word
Program Flowchart).
The Status Register must be read in order to
check that the PC has started (see Table 6 and
Figure 6).
Program Phase. The Program Phase requires
n+1 Bus Write operations, where n is the number
of Words, to execute the programming phase (re-
fer to Table 4, Multiple Word Program and Figure
5, Multiple Word Program Flowchart).
Before any Bus Write operation of the Program
Phase, the Status Register must be read in order
to check that the PC is ready to accept the opera-
tion (see Table 6 and Figure 6).
The Program Phase is executed in three different
sub-phases:
1. The first Bus Write operation of the Program
2. Each subsequent Bus Write operation latches
Phase (the 4th of the command) latches the
Start Address and the first Word to be
programmed.
the next Word to be programmed and
automatically increments the internal Address
Bus. It is not necessary to provide the address
of the location to be programmed but only a
Continue Address, CA (A17 to A20 equal to the
PP
must be set to V
PP
is set either V
HH
during Multiple Word
IL
or V
IH
the com-