am41pds3224d Meet Spansion Inc., am41pds3224d Datasheet - Page 23

• Manufacturer Part Number: am41pds3224d
• Description: 32 Mbit 2 M ? 16-bit Cmos 1.8 Volt-only, Simultaneous Operation Page Mode Flash Memory And 4 Mbit 512 K ? 8-bit/256 K ? 16-bit Static Ram Preliminary
• Manufacturer: Meet Spansion Inc.

The system must provide the proper signals to the
control pins to prevent unintentional writes when V
is greater than V
Write Pulse “Glitch” Protection
Noise pulses of less than 5 ns (typical) on OE#, CE#f
or WE# do not initiate a write cycle.
Logical Inhibit
Write cycles are inhibited by holding any one of OE# =
V
FLASH COMMAND DEFINITIONS
Writing specific address and data commands or se-
quences into the command register initiates device op-
erations. Table 10 defines the valid register command
sequences. Writing incorrect address and data val-
ues or writing them in the improper sequence resets
the device to reading array data.
All addresses are latched on the falling edge of WE#
or CE#, whichever happens later. All data is latched on
the rising edge of WE# or CE#, whichever happens
first. Refer to the AC Characteristics section for timing
diagrams.
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 ready to read array data
after completing an Embedded Program or Embedded
Erase algorithm.
After the device accepts an Erase Suspend command,
the device enters the erase-suspend-read mode, after
w h i c h t h e s y s t e m c a n r e a d d a t a f r o m a n y
non-erase-suspended sector. After completing a pro-
gramming operation in the Erase Suspend mode, the
system may once again read array data with the same
exception. See the Erase Suspend/Erase Resume
Commands section for more information.
The system must issue the reset command to return
the device to the read (or erase-suspend-read) mode
if DQ5 goes high during an active program or erase
operation, or if the device is in the autoselect mode.
See the next section, Reset Command, for more infor-
mation.
See also Requirements for Reading Array Data in the
MCP Device Bus Operations section for more informa-
tion. The Read-Only Operations table provides the
read parameters, and Figure 15 shows the timing dia-
gram.
22
IL
, CE#f = V
IH
or WE# = V
LKO
.
IH
. To initiate a write cycle,
P R E L I M I N A R Y
Am41PDS3224D
CC
CE#f and WE# must be a logical zero while OE# is a
logical one.
Power-Up Write Inhibit
If WE# = CE#f = V
the device does not accept commands on the rising
edge of WE#. The internal state machine is automati-
cally reset to reading array data on power-up.
Reset Command
Writing the reset command resets the device to the
read or erase-suspend-read mode. Address bits are
don’t cares for this command.
The reset command may be written between the se-
quence cycles in an erase command sequence before
erasing begins. This resets the device to the read
mode. Once erasure begins, however, the device ig-
nores 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
the read mode. If the program command sequence is
written while the device is in the Erase Suspend mode,
writing the reset command returns the device to the
erase-suspend-read mode. Once programming be-
gins, however, the device ignores reset commands
until the operation is complete.
The reset command may be written between the se-
quence cycles in an autoselect command sequence.
Once in the autoselect mode, the reset command
must be written to return to the read mode. If the de-
vice entered the autoselect mode while in the Erase
Suspend mode, writing the reset command returns the
device to the erase-suspend-read mode.
If DQ5 goes high during a program or erase operation,
writing the reset command returns the device to the
read mode (or erase-suspend-read mode if the device
was in Erase Suspend).
Autoselect Command Sequence
The autoselect command sequence allows the host
system to access the manufacturer and device codes,
and determine whether or not a sector is protected.
Table 10 shows the address and data requirements.
The autoselect command sequence may be written to
a n a d d r e s s t h a t i s e i t h e r i n t h e r e a d o r
erase-suspend-read mode. The autoselect command
may not be written while the device is actively pro-
gramming or erasing.
IL
and OE# = V
IH
during power up,
May 13, 2002