BS640HD9V datasheet(26/89 Pages) AMD

26 / 89 page

Am29BDS128H/Am29BDS640H

27024B3 May 10, 2006

D A TA

SH EE T

Write Protect (WP#)

The Write Protect feature provides a hardware method

of protecting the four outermost sectors. This function

is provided by the WP# pin and overrides the previ-

ously discussed Sector Protection/Unprotection

method.

If the system asserts VIL on the WP# pin, the device

disables program and erase functions in the eight “out-

ermost” 4 Kword boot sectors.

If the system asserts VIH on the WP# pin, the device

reverts to whether the boot sectors were last set to be

protected or unprotected. That is, sector protection or

unprotection for these sectors depends on whether

they were last protected or unprotected using the

method described in “PPB Program Command” sec-

tion on page 43.

Note that the WP# pin must not be left floating or un-

connected; inconsistent behavior of the device may re-

sult.

Low VCC Write Inhibit

When VCC is less than VLKO, the device does not

accept any write cycles. This protects data during VCC

power-up and power-down. The command register and

all internal program/erase circuits are disabled, and the

device resets to reading array data. Subsequent writes

are ignored until VCC is greater than VLKO. The system

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.

COMMON FLASH MEMORY INTERFACE

(CFI)

The Common Flash Interface (CFI) specification out-

lines device and host system software interrogation

handshake, which allows specific vendor-specified

software algorithms to be used for entire families of

devices. Software support can then be device-indepen-

dent, 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 Quer y 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 8-11. To terminate 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 autoselect mode. The device

enters the CFI query mode, and the system can read

CFI data at the addresses given in Tables 8-11. The

system must write the reset command to return the

device to the autoselect mode.

For further information, please refer to the CFI Specifi-

cation and CFI Publication 100, available via the AMD

site at the following URL:

http://www.amd.com/flash/cfi.

Alternatively, contact an AMD representative for copies

Table 8.

CFI Query Identification String

Addresses

Data

Description

10h

11h

12h

0051h

0052h

0059h

Query Unique ASCII string “QRY”

13h

14h

0002h

0000h

Primary OEM Command Set

15h

16h

0040h

0000h

Address for Primary Extended Table

17h

18h

0000h

Alternate OEM Command Set (00h = none exists)

19h

1Ah

0000h

Address for Alternate OEM Extended Table (00h = none exists)

BS640HD9V Datasheet(PDF) 26 Page - Advanced Micro Devices

BS640HD9V Datasheet(HTML) 26 Page - Advanced Micro Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89

Datasheet Download

Link URL