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Altera_Forum
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11 years ago

DDR2 Altmemphy Read and write through Nios

I am using a DDR2 altmemphy controller IP for

Cyclone III FPGA EP3C120F780C7

DDR2 IC: MT47H32M8BP-3X1 for read/write application using nios-ii processor.

QSYS Connections are as shown in the ddr2_qsys.xps file below.

Included files.

1.ddr2_altmemphy.v top level file.

2.ddr2_altmemphy.qsf

3.ddr_altmemphy.out.sdc

4.altpll1.v

5.altpll1.qip

6.alt_ddr2.qsys

50MHz input clock

100MHz DDR2 altmemphy IP clock=PLL Reference Clock

Memory Clock Frequency: 150 MHz

Clarifications:

1. Is the Qsys system interconnection correct?

2.I have set DDR2 memory as both instruction and data memory, so when the processors compiles and executes the sample nios-ii application from bsp hello_world program it should display "Hello from Nios" in the nios-II console, but i am getting failed to download the elf error, what might be the reason?

3. How to write to the memory from the processor side, what is the command syntax? and what is the command syntax to read from the DDR2 memory?

4. What is the command from the processor side to control bank select ?

Regards,

Sriram

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    11 years ago

    Hello Sriram,

    --- Quote Start ---

    1. Is the Qsys system interconnection correct?

    --- Quote End ---

    According to me,

    1) jtag_debug_module_reset should be connected only to reset of jtag_uart_o,

    2) reset_request_n of DDR2 should not be connected to soft_reset_n. Also it should not be connected to reset CPU. ( Not sure about this. I think you can keep reset_request_n unconnected. )

    --- Quote Start ---

    2.I have set DDR2 memory as both instruction and data memory, so when the processors compiles and executes the sample nios-ii application from bsp hello_world program it should display "Hello from Nios" in the nios-II console, but i am getting failed to download the elf error, what might be the reason?

    --- Quote End ---

    Downloading ELF process failed issue is being faced by many people. You may also find many threads regarding this. One reason for this is that memory is not being accessed correctly due to some reason(?). Obviously you would have checked all your pin assignments. I was also facing same issue few days before in our board. I was able to solve that by not using "Create global reset network" in Qsys and connecting reset to only those items which seemed suitable. ( Someone in one thread has mentioned this and I tried that.) I would like you to try this.

    Have a nice day.:)

    Bhaumik