AM29BDS128HE8 datasheet(50/89 Pages) SPANSION

50 / 89 page

Am29BDS128H/Am29BDS640H

27024B3 May 10, 2006

D A TA

SH EE T

WRITE OPERATION STATUS

The device provides several bits to determine the

status of a program or erase operation: DQ2, DQ3,

DQ5, DQ6, and DQ7. Table 23, “Write Operation

Status,” on page 52 and the following subsections

describe the function of these bits. DQ7 and DQ6 each

offers a method for determining whether a program or

erase operation is complete or in progress.

DQ7: Data# Polling

The Data# Polling bit, DQ7, indicates to the host

system whether an Embedded Program or Erase algo-

rithm is in progress or completed, or whether a bank is

in Erase Suspend. Data# Polling is valid after the rising

edge of the final WE# pulse in the command sequence.

During the Embedded Program algorithm, the device

outputs on DQ7 the complement of the datum pro-

grammed to DQ7. This DQ7 status also applies to pro-

g r am ming dur ing Er ase Suspend. When t h e

Embedded Program algorithm is complete, the device

outputs the datum programmed to DQ7. The system

must provide the program address to read valid status

information on DQ7. If a program address falls within a

protected sector, Data# Polling on DQ7 is active for

approximately tPSP, then that bank returns to the read

mode.

During the Embedded Erase algorithm, Data# Polling

produces a “0” on DQ7. When the Embedded Erase

algorithm is complete, or if the bank enters the Erase

Suspend mode, Data# Polling produces a “1” on DQ7.

The system must provide an address within any of the

sectors selected for erasure to read valid status infor-

mation on DQ7.

After an erase command sequence is written, if all

sectors selected for erasing are protected, Data#

Polling on DQ7 is active for approximately tASP, then the

bank returns to the read mode. If not all selected

sectors are protected, the Embedded Erase algorithm

erases the unprotected sectors, and ignores the

selected sectors that are protected. However, if the

system reads DQ7 at an address within a protected

sector, the status may not be valid.

Just prior to the completion of an Embedded Program

or Erase operation, DQ7 may change asynchronously

with DQ6–DQ0 while Output Enable (OE#) is asserted

low. That is, the device may change from providing

status information to valid data on DQ7. Depending on

when the system samples the DQ7 output, it may read

the status or valid data. Even if the device has com-

pleted the program or erase operation and DQ7 has

valid data, the data outputs on DQ6-DQ0 may be still

invalid. Valid data on DQ7-DQ0 will appear on succes-

sive read cycles.

Table 23, “Write Operation Status,” on page 52 shows

the outputs for Data# Polling on DQ7. Figure 8, “Data#

Polling Algorithm,” on page 48 shows the Data# Polling

algo r i thm. F i gure 40, “Data# Po lling Timings

(During Embedded Algorithm),” on page 76 in the AC

Characteristics section shows the Data# Polling timing

diagram.

Notes:

1. VA = Valid address for programming. During a sector

erase operation, a valid address is any sector address

within the sector being erased. During chip erase, a valid

address is any non-protected sector address.

2. DQ7 should be rechecked even if DQ5 = “1” because

DQ7 may change simultaneously with DQ5.

Figure 8.

Data# Polling Algorithm

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