E

28F020

15

Data = 00H?

Program All

Bytes to 00H

Apply V

PPH

(1)

ADDR = 00H

PLSCNT = 0

Time Out 10 ms

Time Out 6 µs

Read Data

from Device

Data = FFH?

Inc

PLSCNT =

1000?

Last Address?

Erasure

Completed

Erase Error

Write Erase

Set-Up Cmd

Write Erase Cmd

Write Read Cmd

Apply V

PPL

(1)

Apply V

PPL

(1)

Write Erase

Verify Cmd

Increment Addr

Y

Bus

Operation

Comments

Entire Memory Must = 00H

Before Erasure

Use Quick-Pulse

Programming Algorithm

(Figure 4)

Standby

Wait for V

(1)

Initialize Addresses and

Pulse-Count

Write

Data = 20H

Write

Data = 20H

Stand-by

Duration of Erase Operation

(t

Write

Addr = Byte to Verify;

Data = A0H; Stops Erase

Standby

t

WHGL

Read

Read Byte to Verify Erasure

Standby

Compare Output to FFH

Increment Pulse-Count

Standby

Wait for V

(1)

N

Y

N

N

N

Y

Y

Command

Set-Up

Erase

Erase

Verify

Write

Data = 00H, Resets the

Register for Read Operations

Read

0245_05

NOTES:

1.

See

2.

Erase Verify is performed only after chip-erasure. A final read/compare may be performed (optional) after the register is

written with the Read command.

3.

Refer of

Principles of Operation.

4.

Caution: The algorithm must be followed to ensure proper and reliable operation of the device.

Figure 5. 28F020 Quick-Erase Algorithm