ATMEGA640 datasheet(192/436 Pages) MICROCHIP

Part #	ATMEGA640

Description	8-bit Microcontroller with 16/32/64KB In-System Programmable Flash

PDF	436 Pages

Scroll/Zoom	100%

Manufacturer	MICROCHIP [Microchip Technology]

Direct Link	http://www.microchip.com

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ATmega640/V-1280/V-1281/V-2560/V-2561/V [DATASHEET]

DS40002211A

When the SPI is enabled, the data direction of the MOSI, MISO, SCK, and SS pins is overridden according to

Table 21-1. For more details on automatic port overrides, refer to “Alternate Port Functions” on page 72.

Note:

1. See “Alternate Functions of Port B” on page 76 for a detailed description of how to define the direction of the user

defined SPI pins.

The following code examples show how to initialize the SPI as a Master and how to perform a simple transmission.

DDR_SPI in the examples must be replaced by the actual Data Direction Register controlling the SPI pins. DD_-

MOSI, DD_MISO and DD_SCK must be replaced by the actual data direction bits for these pins. For example, if

MOSI is placed on pin PB5, replace DD_MOSI with DDB5 and DDR_SPI with DDRB.

Table 21-1.

SPI Pin Overrides(1)

Direction, Master SPI

Direction, Slave SPI

MOSI

User Defined

Input

MISO

Input

User Defined

SCK

User Defined

Input

User Defined

Input

ATMEGA640 Datasheet(PDF) 192 Page - Microchip Technology