Not

4-51

Programming Interface

Every code byte in the Flash array can be written and the

entire array can be erased by using the appropriate combi-

nation of control signals. The write operation cycle is self-

timed and once initiated, will automatically time itself to

completion.

All major programming vendors offer worldwide support for

the Atmel microcontroller series. Please contact your local

programming vendor for the appropriate software revision.

Flash Programming Modes

Note:

1. Chip Erase requires a 10-ms PROG pulse.

Figure 3. Programming the Flash

Figure 4. Verifying the Flash

Mode

RST

PSEN

ALE/PROG

P2.6

P2.7

P3.6

P3.7

Write Code Data

H

L

12V

L

H

H

H

Read Code Data

H

L

H

H

L

L

H

H

Write Lock

Bit - 1

H

L

12V

H

H

H

H

Bit - 2

H

L

12V

H

H

L

L

Bit - 3

H

L

12V

HL

HL

Chip Erase

H

L

12V

H

L

L

L

Read Signature Byte

H

L

H

H

L

L

L

L

(1)

P1

P2.6

P3.6

P2.0 - P2.3

A0 - A7

ADDR.

OOOOH/OFFFH

T

SEE FLASH

PROGRAMMING

MODES

ABLE

3-12 MHz

A8 - A11

P0

+5V

P2.7

PGM

DATA

PROG

V/V

IH

PP

V

IH

ALE

P3.7

XTAL2

EA

RST

PSEN

XTAL1

GND

V

CC

AT89LV51

CC