AT89LP2052 datasheet(63/90 Pages) ATMEL

63 / 90 page

3547F–MICRO–6/06

AT89LP2052/LP4052

22.4.8

Write User Signature Page

Function:

• Programs 1 to 32 bytes of data into the User Signature Row.

• The User Row Programming Fuse must be enabled before writing to the User Signature Row.

• The byte address (offset in page) is initialized to bits [4:0] of the low address byte. One byte

of data is loaded from P1 for the current address by the positive edge of a XTAL1 pulse. The

internal address is incremented by one on the negative edge of the XTAL1 pulse. The

address will wrap around to the 1st byte of the page when incremented past 31, however

previously loaded bytes should not be re-loaded.

Usage:

Bring CS (P3.2) low.

Drive P1 to AAh and pulse XTAL1 high.

Drive P1 to 52h and pulse XTAL1 high.

Drive P1 to 00h and pulse XTAL1 high.

Drive P1 with bits [4:0] of address and pulse XTAL1 high.

To write only previously loaded data, bring CS high before loading additional bytes. To

load data bytes, drive data on P1 and pulse XTAL1 high to load one byte and increment

to the next address. Repeat for additional bytes. Only 1-32 bytes may be programmed

at one time, including any bytes loaded by a previous load page buffer command. Bytes

should not be loaded more than once.

Bring CS high.

Wait 2 ms, monitor P3.1, or poll data/status.

Note:

It is not possible to skip bytes while loading data during write. To load non-contiguous bytes in a

page, use the Load Page Buffer command.

Figure 22-12. Write User Signature Page Sequence

Note:

The waveform on this page is not to scale.

AAh

52h

00h

000bbbbb

DIN 0

XTAL1

DIN 1

DIN n

RDY/BSY

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