Hello,
I remembered I'm owning a JTAG-Dongle...
It is an Olimex ARM-USB-OCD. In the meantime I opened my DS2202A, attached the JTAG, downloaded the bfin-uclinux stuff and started urjtag:
jtag> cable arm-usb-ocd
Connected to libftdi driver.
jtag> frequency 500000
Setting TCK frequency to 500000 Hz
jtag> detect
warning: TDO seems to be stuck at 0
jtag>
Lower frequencies didn't work either...
So after fiddling a little bit I assume that the U
tst Voltage (3.3V) on Pin 1 on the JTAG header is to weak. According to the schematic posted above it is connected via a pull-up of 10k to 3.3 Volts. The voltage drops to about 1.8V when I connect the JTAG-dongle. That is about 150uA.
So, do you think I just can use an external 3.3V supply for the JTAG-dongle?
Maybe this is the same issue which neamyalo very slow jtag speed? What do you think?