OLIMEX© 2015
ARM-USB-OCD user's manual
CHAPTER 2: DEVICE DESCRIPTION
2. Introduction to the chapter
This chapter features explanation of the interfaces visible to the user. Most of the time those would
be the only parts of the debugger that the user would manipulate or make contact with.
There is only one major difference in the appearance of ARM-USB-OCD and ARM-USB-OCD-H –
the first has two jumpers near the JTAG connector. These jumpers are responsible for the selection
of the voltage output available at the barrel jack – either 5V(by default), 9V or 12V. ARM-USB-
OCD-H lacks such jumpers since it can provide only 5V to the target.
2.1 Status LED
The debugger has one double color (red/green) LED on the top. Upon USB connection the LED
might power up. However, it is mainly meant to indicate programming/debugging in progress. The
red LED should blink when you have an on-going operation (read, write).
2.2 Ports and connectors
The user can freely access the USB and the JTAG connector available. The pinouts and the usage of
those are discussed below.
2.2.1 USB type B connector
The USB type B connector follows the USB 2.0 specification. The connector itself looks like this:
You would most likely need a suitable cable to connect the debugger to your personal computer.
The cable should be USB A-B type. You might find a cable like that in the Olimex web-shop or any
electronics store nearby.
The USB communication is handled by an FTDI chip inside the box. The drivers required are FTDI
ones with modified VID and PID numbers to fit the Olimex own VID and PID.
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