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Reading the signature bytes, Reading the calibration byte, Parallel programming characteristics – Rainbow Electronics ATmega64L User Manual

Page 263: Atmega16(l)

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263

ATmega16(L)

2466B–09/01

Figure 132. Mapping between BS1, BS2 and the Fuse- and Lock Bits during Read

Reading the Signature Bytes

The algorithm for reading the Signature bytes is as follows (refer to “Programming the
Flash” on page 258 for
details on Command and Address loading):

1.

A: Load Command "0000 1000".

2.

B: Load Address Low Byte ($00 - $02).

3.

Set OE to "0", and BS1 to "0". The selected Signature byte can now be read at
DATA.

4.

Set OE to "1".

Reading the Calibration Byte

The algorithm for reading the Calibration byte is as follows (refer to “Programming the
Flash” on page 258 for
details on Command and Address loading):

1.

A: Load Command "0000 1000".

2.

B: Load Address Low Byte, $00.

3.

Set OE to "0", and BS1 to "1". The Calibration byte can now be read at DATA.

4.

Set OE to "1".

Parallel Programming
Characteristics

Figure 133. Parallel Programming Timing, Including some General Timing
Requirements

Fuse low byte

Lock bits

0

1

BS2

Fuse high byte

0

1

BS1

DATA

Data & Contol

(DATA, XA0/1, BS1, BS2)

XTAL1

t

XHXL

t

WL WH

t

DVXH

t

XLDX

t

PLWL

t

WLRH

WR

RDY/BSY

PAGEL

t

PHPL

t

PLBX

t

BVPH

t

XLWL

t

WLBX

t

BVWL

WLRL