AM29F016 datasheet(11/36 Pages) AMD

11 / 36 page

Am29F016

Table 4.

Sector Group Addresses

Write

Device erasure and programming are accomplished

via the command register. The contents of the register

serve as inputs to the internal state machine. The state

machine outputs dictate the function of the device.

The command register itself does not occupy any ad-

dressable memory location. The register is a latch used

to store the commands, along with the address and

data information needed to execute the command. The

command register is written to by bringing WE to VIL,

while CE is at VIL and OE is at VIH. Addresses are

latched on the falling edge of WE or CE, whichever

happens later; while data is latched on the rising edge

of WE or CE, whichever happens first. Standard micro-

processor write timings are used.

Refer to AC Write Characteristics and the Erase/Pro-

gramming Waveforms for specific timing parameters.

Sector Group Protection

The Am29F016 features hardware sector group protec-

tion. This feature will disable both program and erase

operations in any combination of eight sector groups of

memory. Each sector group consists of four adjacent

sectors grouped in the following pattern: sectors 0

–3,

–7, 8–11, 12–15, 16–19, 20–23, 24–27, and 28–31

(see Table 4). The sector group protect feature is en-

abled using programming equipment at the user’s site.

The device is shipped with all sector groups unpro-

tected. Alternatively, AMD may program and protect

sector groups in the factory prior to shipping the device

(AMD’s ExpressFlash™ Service).

It is possible to determine if a sector group is protected

in the system by writing an Autoselect command. Per-

forming a read operation at the address location

XX02H, where the higher order address bits A18, A19,

and A20 is the desired sector group address, will pro-

duce a logical “1” at DQ0 for a protected sector group.

See Table 2 for Autoselect codes.

Temporary Sector Group Unprotect

This feature allows temporary unprotection of previ-

ously protected sector groups of the Am29F016 device

in order to change data in-system. The Sector Group

Unprotect mode is activated by setting the RESET pin

to high voltage (12V). During this mode, formerly pro-

tected sector groups can be programmed or erased by

selecting the sector group addresses. Once the 12 V is

taken away from the RESET pin, all the previously pro-

tected sector groups will be protected again. Refer to

Figures 15 and 16.

Command Definitions

Device operations are selected by writing specific ad-

dress and data sequences into the command register.

Writing incorrect address and data values or writ-

ing them in the improper sequence will reset the

device to the read mode. Table 5 defines the valid

Suspend (B0H) and Erase Resume (30H) commands

are valid only while the Sector Erase operation is in

progress. Moreover, both Reset/Read commands are

functionally equivalent, resetting the device to the read

mode.

A20

A19

A18

Sectors

SGA0

SA0

–SA3

SGA1

SA4

–SA7

SGA2

SA8

–SA11

SGA3

SA12

–SA15

SGA4

SA16

–SA19

SGA5

SA20

–SA23

SGA6

SA24

–SA27

SGA7

SA28

–SA31

AM29F016 数据表(PDF) 11 Page - Advanced Micro Devices

AM29F016 数据表(HTML) 11 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

数据表下载