Atmel AVR1612

AVR1612
3
8282A-AVR-11/10
2.3 Hardware Connection with AT90USB1287’s USART
The Atmel Xplain kit uses the Atmel AT90USB1287’s USART port to implement the
PDI port’s hardware. Figure 2-3 sh
ows the PDI hardware connection between the
AT90USB1287 to the Atmel ATxmega128A1.
Figure 2-3. Hardware connection between AT90USB1287 to ATXmega128A1.
AT90USB1287 ATXmega128A1
XCK
RXD
TXD
220R
220R
PDI
CLK
PDI
DATA
2.4 PDI instruction set
The PDI has a small instruction set that is used for all access to the PDI itself and to
the internal interfaces. All instructions are byte instructions. Most of the instructions
require a number of byte operands following the instruction. The instructions allow for
an external programmer to access the PDI Controller, the NVM Controller and the
NVM memories. Figure 2-4 sho
ws the PDI instructions set, while Table 2-1 shows
gives more details about each instruction.