AT89S2051-24SC datasheet(29/45 Pages) ATMEL

Part #	AT89S2051-24SC

Description	8-bit Microcontroller with 2K/4K Bytes Flash

PDF	45 Pages

Scroll/Zoom	100%

Manufacturer	ATMEL [ATMEL Corporation]

Direct Link	http://www.atmel.com

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29 / 45 page

3390C–MICRO–7/05

AT89S2051/S4051

31. Write Lock Bits/User Fuses

Function:

Program Lock Bits 1 and 2.

Program user fuses.

Usage:

1) Apply “1111” TestCode to P3.7, P3.5, P3.4, P3.3.

Drive Port P1 with fuse data, bits [7:4] for fuses and bits [1:0] for lock bits.

Pulse P3.2 low for 1 µs.

Wait 4 ms, monitor P3.1, or poll data.

Figure 31-1. Write Lock Bits/User Fuses

32. Read Lock Bits/User Fuses

Function:

Read status of Lock Bits 1 and 2.

Read status of user fuses.

Usage:

Apply “0011” TestCode to P3.7, P3.5, P3.4, P3.3.

Read fuse data from Port P1, bits [7:4] for fuses and bits [1:0] for lock bits.

Figure 32-1. Read Lock Bits/User Fuses

DATA

1111

P3.2

XTAL1

P3.3 - P3.7

P1.0 - P1.7

RDY/BSY

High Z

DOUT

0011

P3.2

XTAL1

P3.3. - P3.7

P1.0 - P1.7

RDY/BSY

High Z

AT89S2051-24SC Datasheet(PDF) 29 Page - ATMEL Corporation