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Altera_Forum's avatar
Altera_Forum
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11 years ago

How to determine if I need custom components in Qsys/SOPC or not?

Hi all,

Please forgive me if my question does not make sense to u, I am a newbie to this.

I am going to use BOTH the Nios II processor AND the FPGA on the development board, meaning I need to program Nios II using C language AND also program those logic elements using VHDL.

Basically, the task distribution is as follows:

FPGA: receive signals from Nios ii and pass outputs to the external circuit

Nios ii: receive signals from FPGA's ADC, do all the processing tasks such as arithmetic operation, sort ascending/descending, comparison if-else etc, pass outputs to the FPGA

What I don't know: My question is, in my case, how do I know if I need custom components in the Qsys/sopc tool? What are the criteria if we need to create custom components?

Does it mean that if the FPGA is not doing any processing (just passing inputs and outputs), there is no need to have custom components?

If I do not create the custom component, how can I set those signals readdata, writedata, read, write, address, chipselect as we did in custom component? For instance, when readdata is activated, data will be read from slave, with nios ii as the master etc.

Thank you in advance.

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    Basically, what I want to do is: FPGA receive signals from Nios ii and pass these signals to Mosfet switches (does it mean that since Mosfet signals are external components not on the board, so I need a custom component for this purpose?). Then, FPGA sends voltage and current signals from ADC to the Nios ii.

    I just don't know how to determine if I need custom components, if I need, I know how to set those chipselect, readdata, writedata, conduit signals etc where I can set like when readdata is activated, nios ii is going to read data from FPGA. But if no custom components are created, how do we perform this readdata for instance? I hope I made my question clear this time, sorry.

    FPGA: receive signals from Nios ii and pass outputs to the external circuit

    Nios ii: receive signals from FPGA's ADC, do all the processing tasks such as arithmetic operation, sort ascending/descending, comparison if-else etc, pass outputs to the FPGA
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    I understand that if I am going to use custom made component in Qsys, I should refer to the Avalon interface specification:http://www.altera.com/literature/manual/mnl_avalon_spec.pdf

    But, before going into this, I want to ask one question, since I need to send signals from the board to Mosfet switches (which are NOT on the board), does it mean I for sure need to have custom component? I just want to make sure I understand correctly.
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    Custom component is something that you can write a piece of code and import in qsys connect to nios II.

    For example you want to display LED's you can use PIO connect to NiosII and write something from software but if you want control intensity of LED you can't use PIO,write a piece of code like PWM and import in qsys and glow led from software and at the same time you can control intensity.