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5949 Discussions

Custom IP Simulation in ModelSim

Altera_Forum
Honored Contributor II
820 Views

Hi all, 

 

I have a Custom IP developed in VHDL and i am able to communicate with the NiosII Soft processor.But when i simulate the Nios II processor,the communication between the Nios II and the IP is not as expected. 

If i watch the slave_write and chip_select ,then in between the consecutive slave_write pulses,there comes a slave_read pulse also. 

How to avoid the slave_read pulses in between?
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7 Replies
Altera_Forum
Honored Contributor II
77 Views

Usually, the slave write/read is controlled in the application code. You might want to check your code and see whether you have inserted the reads.

Altera_Forum
Honored Contributor II
77 Views

I have checked the application code .I am only allowing two writes from the code.No read operation i am doing in between. 

But when i simulate in modelsim,it shows a read signal in between the two write operation.
Altera_Forum
Honored Contributor II
77 Views

Are you using the io.h to perform IOWR_32DIRECT? Is Nios the only master to your custom IP?

Altera_Forum
Honored Contributor II
77 Views

Is the write instruction writing a whole word, or only a partial word - ie is the processor reading the full word, modifying the data and then writing back the full word having left the top byte unchanged, or similar?

Altera_Forum
Honored Contributor II
77 Views

 

--- Quote Start ---  

Are you using the io.h to perform IOWR_32DIRECT? Is Nios the only master to your custom IP? 

--- Quote End ---  

 

 

Yes,I am using io.h to perform the write operation and Nios is the only master to the custom IP
Altera_Forum
Honored Contributor II
77 Views

 

--- Quote Start ---  

Is the write instruction writing a whole word, or only a partial word - ie is the processor reading the full word, modifying the data and then writing back the full word having left the top byte unchanged, or similar? 

--- Quote End ---  

 

 

The write instruction is writing the whole word(32 bit data)
Altera_Forum
Honored Contributor II
77 Views

Did you trace back the read to Nios?  

What happens if you remove the writes from your application? 

 

What is your custom IP doing?
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