User guide

Evaluation Kit Hardware
Evaluation Kit (EK) User Guide 4-51
11115A–ATARM–27-Jul-11
Table 4-22. JTAG/ICE Connector J13 Signal Descriptions
Pin Mnemonic Description
1 VTref. 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 Vsupply. 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.
16 GND Common ground
17 RFU This pin is not connected in SAM-ICE.
18 GND Common ground
19 RFU This pin is not connected in SAM-ICE.
20 GND Common ground