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CHAPTER 9
Flasher ARM 20-pin JTAG/SWD Connector
PIN
SIGNAL
TYPE
Description
17 DBGRQ
NC
This pin is not connected in Flasher ARM. It is reserved for
compatibility with other equipment to be used as a debug
request signal to the target system. Typically connected to
DBGRQ if available, otherwise left open.
19 5V-Target
supply
Output This pin is used to supply power to some eval boards. Typi-
cally left open on target hardware.
Pins 4, 6, 8, 10, 12, 14, 16, 18, 20 are GND pins connected to GND in Flasher ARM. They
should also be connected to GND in the target system.
9.1.2 Pinout SWD
The 20-pin connector of Flasher is also compatible to ARM’s Serial Wire Debug (SWD)
interface.
The following table lists the Flasher ATE SWD pinout.
PIN
SIGNAL
TYPE
Description
1
VTref
Input
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 of the target board
and must not have a series resistor.
2
Vsupply
NC
This pin is not connected in Flasher ATE. It is reserved for
compatibility with other equipment. Connect to Vdd or leave
open in target system.
3
Not Used
NC
This pin is not used by Flasher ATE. If the device may also
be accessed via JTAG, this pin may be connected to nTRST,
otherwise leave open.
5
Not used
NC
This pin is not used by Flasher ATE. If the device may al-
so be accessed via JTAG, this pin may be connected to TDI,
otherwise leave open.
7
SWDIO
I/O
Single bi-directional data pin.
9
SWCLK
Output
Clock signal to target CPU.
It is recommended that this pin is pulled to a defined state
of the target board. Typically connected to TCK of target
CPU.
11 Not used
NC
This pin is not used by Flasher ATE. This pin is not used by
Flasher ATE when operating in SWD mode. If the device may
also be accessed via JTAG, this pin may be connected to
RTCK, otherwise leave open.
13 SWO
Output Serial Wire Output trace port. (Optional, not required for
SWD communication.)
Flasher ATE User Guide (UM08035)
© 2017-2018 SEGGER Microcontroller GmbH
