Microchip Technology AVR128DB48 Curiosity Nano, Руководство пользователя по оборудованию

Страница: 22 / 46

Figure 4-9. Programming and Debugging Connections to Debugger
GPIO straps (bottom side)
Info: Cutting the connections to the debugger will disable programming, debugging, and data streaming
from the AVR128DB48 mounted on the board.
Tip: Solder in 0Ω resistors across the footprints or short-circuit them with solder to reconnect the signals
between the on-board debugger and the AVR128DB48.
4.5.4 Connecting to External Microcontrollers
The figure and table below show where the programming and debugging signals must be connected to program and
debug external microcontrollers. The on-board debugger can supply power to the external hardware, or use an
external voltage as a reference for its level shifters. Read more about the power supply in
4.3 Power Supply .
The on-board debugger and level shifters actively drive data and clock signals (DBG0, DBG1, and DBG2) used for
programming and debugging, and in most cases, the external resistor on these signals can be ignored. Pull-down
resistors are required on the ICSP
™
data and clock signals to debug PIC
®
microcontrollers.
DBG3 is an open-drain connection and requires a pull-up resistor to function.
AVR128DB48 Curiosity Nano has a pull-up resistor, R200, connected to its #RESET signal (DBG3). The location of
the pull-up resistor is shown in the
8.2 Assembly Drawing in the appendix.
Remember:
• Connect GND and VTG to the external microcontroller
• Tie the VOFF pin to GND if the external hardware has its own power supply
• Make sure there are pull-down resistors on the ICSP data and clock signals (DBG0 and DBG1) to
support the debugging of PIC microcontrollers
AVR128DB48 Curiosity Nano
Curiosity Nano
©
2020 Microchip Technology Inc.
User Guide
DS50003037A-page 22