AVR1612
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8282A-AVR-11/10
5 The Hierarchy of the code
The code of this application can be divided into four layers.
shows the
hierarchy of this application code.
1. Application Layer: Integrate each module. User code may go into this layer.
2. The high level target XMEGA NVM driver, which interface the low level PDI
driver.
3. The low level PDI driver uses the reduced instructions set for the PDI interface to
communicate with the programmer USART driver for basic PDI operations.
4. AT90USB1287 USART driver is responsible for setting up the physical USART
module based on the settings given from the PDI low level layer.
Figure 5-1.
The modules graph of the sample code.