OLIMEX© 2015
ARM-USB-OCD user's manual
2.2.3 RS232 connector
After the drivers are properly installed ARM-USB-OCD creates a separate virtual COM port which
acts as a standard COM port. You can access it by the DB9 RS232 male connector. The RS232
function works simultaneously with the JTAG interface and functions.
Table 4. RS232 male connector
Pin #
Signal Name
1
RS232 DCD
2
RS232 RX
3
RS232 TX
4
RS232 DTR
5
GND
6
RS232 DSR
7
RS232 RTS
8
RS232 CTS
9
Not connected
2.2.4 Power out barrel jack
The debugger has a center-positive DC barrel jack. It provides DC voltage output. This option is
especially helpful if you just want to power your target board without establishing a JTAG
connection. The power supply available at the barrel jack is taken from the USB type B.
Do not provide power to the DC barrel jack! This is not a power input!
An extension cable that fits the barrel jack is included in the package. It has a total length of 30
centimeters. The cable can be used between the barrel jack of the debugger and the barrel jack of
the target board.
The DC barrel jack has a 2.0mm thick inner pin and 6.3mm hole diameter. The inner pin carries the
positive voltage. The corresponding power supply plug (or female jack) that fits the above DC
barrel has 2.1mm hole diameter and 5.5mm outer diameter. The cable which is included in the
package of the debugger has such female jacks at both ends.
The voltage available at the power out barrel jack depends on the exact product you have! The
voltage available at the PWR_OUT barrel jack might vary ARM-USB-OCD or ARM-USB-OCD-H.
By default both debugger designs can provide 5V DC to the PWR_OUT jack. However, ARM-
USB-OCD has two jumpers that can enable 9V DC voltage output or 12V DC voltage output. The
power supply jumpers are on right side of the 2×10 pin JTAG connector.
- If both jumpers are open the output voltage is 12VDC
- If right jumper is closed the output voltage is 9VDC
- If left jumper is closed the output voltage is 5VDC (this is the default setting)
A typical connection using the DC barrel jack is shown on the next page:
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