AM29LV640MT110REF datasheet(41/66 Pages) AMD

41 / 66 page

February 1, 2007 26190C8

Am29LV640MT/B

D A TA

SH EET

RY/BY#: Ready/Busy#

The RY/BY# is a dedicated, open-drain output pin

which indicates whether an Embedded Algorithm is in

progress or complete. The RY/BY# status is valid after

the rising edge of the final WE# pulse in the command

sequence. Since RY/BY# is an open-drain output, sev-

eral RY/BY# pins can be tied together in parallel with a

pull-up resistor to V

CC.

If the output is low (Busy), the device is actively eras-

ing or programming. (This includes programming in

the Erase Suspend mode.) If the output is high

(Ready), the device is in the read mode, the standby

mode, or in the erase-suspend-read mode. Table 14

shows the outputs for RY/BY#.

DQ6: Toggle Bit I

Toggle Bit I on DQ6 indicates whether an Embedded

Program or Erase algorithm is in progress or com-

plete, or whether the device has entered the Erase

Suspend mode. Toggle Bit I can be read at any ad-

dress, and is valid after the rising edge of the final

WE# pulse in the command sequence (prior to the

program or erase operation), and during the sector

erase time-out.

During an Embedded Program or Erase algorithm op-

eration, successive read cycles to any address cause

DQ6 to toggle. The system can use either OE# or CE#

to control the read cycles. When the operation is com-

plete, DQ6 stops toggling.

After an erase command sequence is written, if all sectors

selected for erasing are protected, DQ6 toggles for approxi-

mately 100 µs, then returns to reading array data. If not all

selected sectors are protected, the Embedded Erase algo-

rithm erases the unprotected sectors, and ignores the se-

lected sectors that are protected.

The system can use DQ6 and DQ2 together to determine

whether a sector is actively erasing or is erase-suspended.

When the device is actively erasing (that is, the Embedded

Erase algorithm is in progress), DQ6 toggles. When the de-

vice enters the Erase Suspend mode, DQ6 stops toggling.

However, the system must also use DQ2 to determine

which sectors are erasing or erase-suspended. Alterna-

tively, the system can use DQ7. See DQ7: Data# Polling on

page 38).

If a program address falls within a protected sector,

DQ6 toggles for approximately 1

μs after the program

command sequence is written, then returns to reading

array data.

DQ6 also toggles during the erase-suspend-program

mode, and stops toggling once the Embedded Pro-

gram algorithm is complete.

Table 14 shows the outputs for Toggle Bit I on DQ6.

Figure 9 shows the toggle bit algorithm. Figure 21 in

AC Characteristics shows the toggle bit timing dia-

grams. Figure 22 shows the differences between DQ2

and DQ6 in graphical form. See also DQ2: Toggle Bit II

on page 40.

AM29LV640MT110REF 数据表(PDF) 41 Page - Advanced Micro Devices

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