Hi.
I’ m a new user of OMAP-L137 EVM rev. D (I have received the board few days ago) and I have many problems to solve.
I understand that starting with DSP is not easy (also if I have used successfully in the past two different ADI demo board) so the problems are a normal way to work.
I followed the instructions at:
http://tiexpressdsp.com/index.php/Getting_Started_Guide_for_C6747#Installing_the_SDK_Software
I choose to start only with DSP674x core (at the moment I’ m not interested in the ARM core)
Since I’ m an audio developer I have compiled and loaded the audioSample.pjt.
The program run normally in to the target board without error but at the line out not signal is present.
I have connected at the LINE IN input a stereo jack with 1kHz signal that I can see with an Oscilloscope.
I have checked that L/R signals from LINE IN arrive at the pins 3, 5 of the TVL320AIC3106.
I have also measured the signals at some interesting Codec pins
Pin 38 1,41 MHz clock
Pin 39 44,1 kHz pulse
Pin 40 data in (from DSP)
Pin 41 data out (from codec)
The pin 41 behaviour is strange. On this pin need to be present the data from codec to the DSP but with the oscilloscope on 1V sensitivity I see a very small amplitude signal. If I increase the Oscilloscope sensitivity to 100mV division I see a typical digital signal of a data transmission but a very low level. If I stop/start the 1kHz Line in signal something change in the data out signal. So I think the codec work well (?) but
- the data out signal is shorted to ground after the R197 resistor
- maybe I need to setup a pull-up resistor inside the DSP input.
I have verified also the U3 IC between the codec and the DSP. At the input and output of U3 are present the 1,41MHz clock and 44,1 kHz, so normally come to DSP inputs but the Data out and Data in are zero.
In particular I have verified that on the pin41 of the codec I can see the signal on the oscilloscope with 100mV sensitivity; on the other side of R197 the signal is zero, like the resistor is shorted to ground.
I think that there is a wrong configuration of the switches on the board.
So attached there is the configuration of all the switches present on the EVM.
Tell me if you need more measurements on the boards to allows you to better understand my problem.
Giuseppe