AM29BDS640G datasheet(20/65 Pages) SPANSION

20 / 65 page

Am29BDS640G

25903C1 October 1, 2003

Prelimin ary

tem must provide the proper signals to the control inputs to prevent unintentional

writes when VCC is greater than VLKO.

Write Pulse “Glitch” Protection

Noise pulses of less than 5 ns (typical) on OE#, CE# or WE# do not initiate a write

cycle.

Logical Inhibit

Write cycles are inhibited by holding any one of OE# = VIL, CE# = VIH or WE# =

VIH. To initiate a write cycle, CE# and WE# must be a logical zero while OE# is a

logical one.

Power-Up Write Inhibit

If WE# = CE# = RESET# = VIL and OE# = VIH during power up, the device does

not accept commands on the rising edge of WE#. The internal state machine is

automatically reset to the read mode on power-up.

VCC and VIO Power-up And Power-down Sequencing

The device imposes no restrictions on VCC and VIO power-up or power-down se-

quencing. Asserting RESET# to VIL is required during the entire VCC and VIO

power sequence until the respective supplies reach their operating voltages. Once

VCC and VIO attain their respective operating voltages, de-assertion of RESET#

to VIH is permitted.

Common Flash Memory Interface (CFI)

The Common Flash Interface (CFI) specification outlines device and host system

software interrogation handshake, which allows specific vendor-specified soft-

ware algorithms to be used for entire families of devices. Software support can

then be device-independent, JEDEC ID-independent, and forward- and back-

ward-compatible for the specified flash device families. Flash vendors can

standardize their existing interfaces for long-term compatibility.

This device enters the CFI Query mode when the system writes the CFI Query

command, 98h, to address 55h any time the device is ready to read array data.

The system can read CFI information at the addresses given in Tables 3-6. To ter-

minate reading CFI data, the system must write the reset command.

The system can also write the CFI query command when the device is in the au-

toselect mode. The device enters the CFI query mode, and the system can read

CFI data at the addresses given in Tables 3-6. The system must write the reset

command to return the device to reading array data.

For further information, please refer to the CFI Specification and CFI Publication

100, available via the web at the following URL: http://www.amd.com/flash/cfi.

Alternatively, contact an sales office or representative for copies of these

documents.

AM29BDS640G Datasheet(PDF) 20 Page - SPANSION