ATmega128 datasheet(211/386 Pages) ATMEL

Il numero della parte	ATmega128

Spiegazioni elettronici	8-bit Microcontroller with 128K Bytes In-System Programmable Flash

PDF	386 Pages

Scroll/Zoom	100%

Produttore elettronici	ATMEL [ATMEL Corporation]

Homepage	http://www.atmel.com

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211 / 386 page

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2467S–AVR–07/09

ATmega128

Even though this example is simple, it shows the principles involved in all TWI transmissions.

These can be summarized as follows:

•

When the TWI has finished an operation and expects application response, the TWINT flag

is set. The SCL line is pulled low until TWINT is cleared.

•

When the TWINT flag is set, the user must update all TWI Registers with the value relevant

for the next TWI bus cycle. As an example, TWDR must be loaded with the value to be

transmitted in the next bus cycle.

•

After all TWI Register updates and other pending application software tasks have been

completed, TWCR is written. When writing TWCR, the TWINT bit should be set. Writing a

one to TWINT clears the flag. The TWI will then commence executing whatever operation

was specified by the TWCR setting.

In the following an assembly and C implementation of the example is given. Note that the code

below assumes that several definitions have been made for example by using include-files.

ATmega128 Scheda tecnica(PDF) 211 Page - ATMEL Corporation