Atmel SAMA5D31-EK, User Manual

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SAMA5D3x-EK User Guide [USER GUIDE]
11180B–ATARM–29-Oct-13
5.4.2 JTAG/ICE Connector
Figure 5-25. JTAG J9
Table 5-5. JTAG/ICE Connector J9 Signal Descriptions
Pin Mnemonic Signal Description
1 VT
ref
3.3V power
This is the target reference voltage. It is used to check if the target has
power, to create the logic-level reference for the input comparators, and
to control the output logic levels to the target. It is normally fed from VDD
on the target board and must not have a series resistor.
2 V
supply
3.3V power
This pin is not connected in SAM-ICE. It is reserved for compatibility with
other equipment. Connect to VDD or leave open in target system.
3
nTRST Target Reset - Active-low
output signal that resets the target.
JTAG Reset. Output from SAM-ICE to the Reset signal on the target
JTAG port. Typically connected to nTRST on the target CPU. This pin is
normally pulled High on the target to avoid unintentional resets when
there is no connection.
4 GND Common ground
5
TDI Test Data Input - Serial data
output line, sampled on the rising
edge of the TCK signal. JTAG data input of target CPU. It is recommended that this pin is pulled
to a defined state on the target board. Typically connected to TDI on
target CPU.
6 GND Common ground
7 TMS Test Mode Select.
JTAG mode set input of target CPU. This pin should be pulled up on the
target. Typically connected to TMS on target CPU. Output signal that
sequences the target's JTAG state machine, sampled on the rising edge
of the TCK signal.
8 GND Common ground
9
TCK Test Clock - Output timing
signal, for synchronizing test logic
and control register access. JTAG clock signal to target CPU. It is recommended that this pin is
pulled to a defined state on the target board. Typically connected to TCK
on target CPU.
10 GND Common ground
11
RTCK - Input Return Test Clock
signal from the target.
Some targets must synchronize the JTAG inputs to internal clocks. To
assist in meeting this requirement, a returned and retimed TCK can be
used to dynamically control the TCK rate. SAM-ICE supports adaptive
clocking which waits for TCK changes to be echoed correctly before
making further changes. Connect to RTCK if available, otherwise to
GND.
12 GND Common ground
13
TDO JTAG Test Data Output -
Serial data input from the target. JTAG data output from target CPU. Typically connected to TDO on
target CPU.
14 GND Common ground
15 nSRST RESET Active-low reset signal. Target CPU reset signal.