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5950 Discussions

problem about dspbuilder input

Altera_Forum
Honored Contributor II
764 Views

I need a source to simulation the project? But I can't find the source? 

I use sine wave to connect "altbus"(the simulink compile error: can't infer data type). I use sine wave to connect "input" it have not output. I find the dspbuilder handbook find it use sine wave to connect "altbus" ,why I cann't get it. How can I simulation the project? I am confused with it .
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4 Replies
Altera_Forum
Honored Contributor II
79 Views

You need to use DSP Builder Input blocks not Altbus blocks to mark the start of your DSP Builder system. An Input block can have ordinary simulink blocks connected to its input and then you can connect DSP Builder blocks to its outputs. Similarly use DSP Builder Output blocks to mark the end of your DSP Builder system.

Altera_Forum
Honored Contributor II
79 Views

I also have a very similar problem using the input block. when i connect my signal to it, it returns nothing on the scope or output that looks nothing like the signal. i'm utterly confused of how it works, is there something on the parameters i need to change. please help! ASAP. 

The image below is what i'm talking about, i'm trying to put the signal below though an FIR filter, but as you can see when i put it through the input block it looks nothing like the oringal signal. i dont know what i'm doing wrong please help me! 

 

https://www.alteraforum.com/forum/attachment.php?attachmentid=4513
Altera_Forum
Honored Contributor II
79 Views

The input block you have there is configured to be a 24-bit integer. You're feeding in a real input with a range from 0 to 2 so it's quantising it. There are only 3 possible values: 0, 1 and 2. 2 doesn't happen because it requires time = pi/2 which your granularity doesn't allow for. 

 

Change the input block to have type signed binary fractional and set the number of fractional bits to something more than 0 and you should see something more like your original signal.
Altera_Forum
Honored Contributor II
79 Views

hi dabuk, 

i have a similar problem. eventhough i went ahead and changed the values for the fractional bit system, i am still not getting anything to show on the scope. Mind you this is before filtering. would be interested if you could look at my thread and help me out. says replace_block and input problem on the title.
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