I have design my own system use BF561. My soft environment is visual dsp4.5. the emulator is HPUSB. it works well when I program on BF533 ez-kit lite .
But , when I connect the emulator header to my own system . And open the visual dsp 4.5. It cannot find my target. it says "visual dsp has detect 0 device int the jtag chain ".
I am sure the crystal works well, the frequency is 20MHz. the VDD_INT is 1.22V and VDD_EXT is 3.3V. Then, I use oscilloscope to find the problem.
the following is the signal on JTAG interface:
when I connect the target from visual dsp4.5.
TCK pin has a series of '0' and '1' . I mean the pin has clock signals for some time.
EMU pin stay at '1' at last.
TMS pin has a rectangle pulse "1" and then come to ' 0 '. ____| |______
TRST pin is '1' at last.
TDI pin is pull to high for some time and then come to '0' at last. I do not think it is data which contains '0' and '1'.
TDO pin do not change at all.
I cannot judge what is the problem.
may be the BGA pins are not solder well? I am not sure.
WOULD YOU PLEASE TELL ME HOW TO FIND THE CAUSE which makes visual dsp4.5 find no target?
thanks a lot!