Atmel ATAVRBFLY Data Sheet
AVR Butterfly User Guide
-25
4271C–AVR–04/05
Table 3-2. USI
3.9
External
DataFlash
DataFlash
An external dataflash is provided with the AVR Butterfly. This is the 4-megabit serial
DataFlash from Atmel, type AT45DB041B. More information about the DataFlash can
be found in the datasheet available at the Atmel web site:
DataFlash from Atmel, type AT45DB041B. More information about the DataFlash can
be found in the datasheet available at the Atmel web site:
http://www.atmel.com/products/DataFlash/
The DataFlash is connected to the SPI interface. This means that in addition to commu-
nicate with the ATmega169 on the AVR Butterfly, it can also be accessed externally
through the ISP connector.
Note:
nicate with the ATmega169 on the AVR Butterfly, it can also be accessed externally
through the ISP connector.
Note:
If the DataFlash is to be accessed externally, the ATmega169 on the AVR But-
terfly must be set to disable its own SPI interface to avoid contention on the
interface.
terfly must be set to disable its own SPI interface to avoid contention on the
interface.
Figure 3-19. DataFlash
Figure 3-20. DataFlash Schematic
AVR Butterfly USI
Pin 1 (USCK/SCL)
Pin 2 (DI/SDA)
Pin 3 (DO)
Pin 4 (GND)