26

AVR32768

32157A-AVR-12/10

Table 14-2.

Nexus port interface checklist.

Signal name

Recommended pin connection

Description

TDI

Test data input, sampled on rising TCK

TMS

Test mode select, sampled on rising TCK

TCK

Test clock, fully asynchronous to system clock frequency

TDO

Test data output, driven on falling TCK

RESET

Device external reset line

EVTI

Event input

MDO[0:5]

Trace data output

EVTO

Event output

MCK0

Trace data output clock

MSE[0:1]

Trace frame control

14.3 aWire port interface

aWire is a single-wire debug solution that offers memory access, programming

capabilities, and On-Chip Debug access. aWire can also be used as a UART when it

is not used for debugging.

A full-duplex mode can be used to increase speed, in which case data is transmitted

on a second pin, DATAOUT.

aWire uses the RESET_N pin for data in/data out. When using aWire, the board reset

duplex communication.

Figure 14-3.

Disconnecting the reset circuitry to allow aWire use.

RESET_N

100 nF

10 kΩ

VDDIO

aWire DATA

Figure 14-4.

aWire with full-duplex communication.