Medbg - Microchip Technology ATmega328P Xplained Mini Manual

Figure 4-5. User LED
4.5

mEDBG

The ATmega328P Xplained Mini board has an embedded debugger/programmer enabling debugging and
programming of the ATmega328P without any additional external equipment.
4.5.1 mEDBG COM Port Connection
The mEDBG provides a CDC COM port connection when connected to a USB host device.
The mEDBG (ATmega32U4) USART is used for communication with the CDC COM port. The USART TX/RX signals
are available on the J104 header and are also connected to the ATmega328P via 0Ω resistors enabling easy
disconnect from the ATmega328P if needed. The RX/TX silkscreen notation next to J104 refers to the RX and TX
pins of the mEDBG (ATmega32U4).
Table 4-7. J104 USART Header
J104 Pin
1 - USART TxD
2 - USART RxD
4.5.2 mEDBG JTAG Interface
The mEDBG (ATmega32U4) JTAG interface is available for programming and debugging of the ATmega32U4 on the
50-mil header in the upper right corner of the kit.
Table 4-8. J100 JTAG Header
J100 Pin Signal Name
1 TCK
2 GND
3 TDO
4 VCC_BOARD
©
2020 Microchip Technology Inc.
USER LED
ATmega32U4 ATmega328P
PD3 PD0 (RxD)
PD2 PD1 (TxD)
Description
ATmega32U4 V
ATmega328P Xplained Mini
D200
LED_12
EL17-21UYC/A3
GND
Function
TxD out from ATmega32U4
RxD in to ATmega32U4
(J301 pin 2)
CC
User Guide
Hardware User Guide
DS50002659B-page 19