AM29LV160DT-70EE Просмотр технического описания (PDF) - Advanced Micro Devices

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AM29LV160DT-70EE

16 Megabit (2 M x 8-Bit/1 M x 16-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory

Advanced Micro Devices 

DQ5: Exceeded Timing Limits

DQ5 indicates whether the program or erase time has

exceeded a specified internal pulse count limit. Under

these conditions DQ5 produces a “1.” This is a failure

condition that indicates the program or erase cycle was

not successfully completed.

The DQ5 failure condition may appear if the system

tries to program a “1” to a location that is previously pro-

grammed to “0.” Only an erase operation can change

a “0” back to a “1.” Under this condition, the device

halts the operation, and when the operation has

exceeded the timing limits, DQ5 produces a “1.”

Under both these conditions, the system must issue the

reset command to return the device to reading array

data.

DQ3: Sector Erase Timer

After writing a sector erase command sequence, the

system may read DQ3 to determine whether or not an

erase operation has begun. (The sector erase timer

does not apply to the chip erase command.) If additional

sectors are selected for erasure, the entire time-out also

applies after each additional sector erase command.

When the time-out is complete, DQ3 switches from “0” to

“1.” The system may ignore DQ3 if the system can

guarantee that the time between additional sector

erase commands will always be less than 50 µs. See

also the “Sector Erase Command Sequence” section.

After the sector erase command sequence is written,

the system should read the status on DQ7 (Data# Poll-

ing) or DQ6 (Toggle Bit I) to ensure the device has ac-

cepted the command sequence, and then read DQ3. If

DQ3 is “1”, the internally controlled erase cycle has be-

gun; all further commands (other than Erase Suspend)

are ignored until the erase operation is complete. If

DQ3 is “0”, the device will accept additional sector

erase commands. To ensure the command has been

accepted, the system software should check the status

of DQ3 prior to and following each subsequent sector

erase command. If DQ3 is high on the second status

check, the last command might not have been ac-

cepted. Table 10 shows the outputs for DQ3.

Table 10. Write Operation Status

Operation

DQ7

(Note 2)

DQ6

DQ5

(Note 1)

DQ3

DQ2

(Note 2)

RY/BY#

Standard Embedded Program Algorithm

DQ7#

Toggle

0

Mode

Embedded Erase Algorithm

0

Toggle

0

N/A

No toggle

0

1

Toggle

0

Erase

Suspend

Mode

Reading within Erase

Suspended Sector

Reading within Non-Erase

Suspended Sector

1

No toggle

0

N/A

Toggle

1

Data

Data

Data

Data

Data

1

Erase-Suspend-Program

DQ7#

Toggle

0

N/A

N/A

0

Notes:

1. DQ5 switches to ‘1’ when an Embedded Program or Embedded Erase operation has exceeded the maximum timing limits.

See “DQ5: Exceeded Timing Limits” for more information.

2. DQ7 and DQ2 require a valid address when reading status information. Refer to the appropriate subsection for further details.

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Am29LV160D

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