Part Number:TMS320C6746
Hello!
We would like to have some help with our design.
We designed and manufactured this board and we have some problems with it.
We manufactured 20 boards and had next problems:
1. The picture that we get from the camera that connecterd to DSP have yellow hue. Replacing camera no helped, but when at board with normal picture we replaced DSP - after replacing the picture accept yellow hue. We had 5 boards that had this issue.
2. After some time of running - there are appeared short circuit between 3.3V and GND. And after DSP replacing the short circuit disappeared. We had 3 board with this problem.
3. After some time of running the JTAG emulator couldn't connect to the board. And we get at Code Composer next error:
After DSP replacing this issue was resolve. We had 7 boards with this problem.
4. The problem that we able to connect to the board with the emulator, but can't burn the Flash - the Code Composer give error :SPI Flash failed" And at debug/stream mode we get next error:
And if you press OK you get:
This problem we had at 4 boards. And even DSP/DDR/Flash replacing didn't helped to sort it out..
For power of the DSP we used recommended TI components and design. Here are the schematic:
At our tests we discovered that we have exceptions at power levels, when because of noise and ripples we have at core 1.3±70mV instead of 1.3±50mV. Same problem with the 1.2V.
The possible problems that maybe make those problems are:
1. The power components placed relatively close to DSP chip - that maybe no so good for right DSP performance.
2. The area for DSP and its components is very small.
The top of layout of the DSP part is:
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When we can see at top DDR K4T1G164QF-BCE7, then DSP and then power components.
The bottom of the same part of DSP:
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The board consists of 10 layers.
We can provide complete layout (*.brd) for review.
Can you please help us in founding possible failure points that we will take into account at the next version of our design.
Thank you in advance