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Altera_Forum's avatar
Altera_Forum
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14 years ago

SOPC with SDRAM Contoller

Hy everyone, I am new in building SOPC.

Here is my objection : creating SOPC with SDRAM to write a simple Hello world on NIOS II by using DE0 development board.

I got an error message from NIOS II on address 0_x100_0000 and 0_x100_D727 (notice that it's 9 bits only). (*attached)

My system contains of :

1. CPU (*attached)

2. onchip_memory (not used in this project)

3. sys_timer_clock

4. jtag_uart

5. SDRAM (contoller) (*attached)

6. PLL (*attached)

I think the main problem was coming from my SDRAM contoller setting or PLL setting.

FYI,

For CPU: memory is attached to SDRAM_0 (*pic 1).

For PLL : input clock is 50MHz (from DE0). I created 2 output clock with 50MHz.each for CPU (CPU_clk) and SDRAM(SDRAM_clk).

After getting the error message, I changed the frequency settings to 130MHz, since I realize that the highest frequency for DE0 SDRAM is at 133Mhz for -7 Mode.

I also calculated the phase shift for SDRAM_clk. From user guide, I calculated the phase shift by using below formula :

Read Lag = tOH (SDRAM) - tH(FPGA) = 2.7-(-0.28) = 2.98 ns

Read Lead = tCO_min(FPGA) - tDH(SDRAM) = 0.85-0.8 = 0.05 ns

Phase Shift = (-2.98+0.05)/2 = -1.465ns

I got tOH and tDH from IS42S16400 SDRAM Time Spec (*attached). tH and tDH from "TImeQuest Timing Analyzer" after compiling my project (*attached).

For SDRAM contoller, I set the Address width with 12 Row , 8 Column , 4 Banks, with 16 bit Data Width. (total = 8MBytes). And I also set some timing spec for this controller. FYI, DE0 has IS42S16400 SDRAM.

As i said , I think my main problem came from SDRAM or PLL.

Please help :o

Any reply will be appreciated.

Best regards,

Yuyex :o

20 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    From Nios properties I see sdram_0 base address is 0x800000 while is loading and verifying addresses 0x1000000 and 0x2008000.

    There's definitely something wrong.

    Are you sure you have associated the Nios project to the right sopc system?
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Thank you for your reply Cris,

    seems like NIOS didn't take the new SOPC system that i've fixed. So i tried to create a new project file and input the new system once more.

    I got below error :

    verifying 01000000 ( 0%)

    verify failed between address 0x1000000 and 0x100d96b

    leaving target processor paused

    Besides, I need to ask if i need to assign input/output pin for this SDRAM in this SOPC?

    Thank you,

    Yuyex:o
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    seems like NIOS didn't take the new SOPC system that i've fixed. So i tried to create a new project file and input the new system once more.

    I got below error :

    verifying 01000000 ( 0%)

    verify failed between address 0x1000000 and 0x100d96b

    leaving target processor paused

    --- Quote End ---

    Something has changed but there's still something wrong if sdram base address is really 0x800000.

    Or is it actually 0x1000000?

    Do you mind posting the picture of your sopc? So I can see all bus connections and base address

    --- Quote Start ---

    Besides, I need to ask if i need to assign input/output pin for this SDRAM in this SOPC?

    --- Quote End ---

    Sure, you must assign sdram pins. But you must do it in Quartus project, not in sopc builder.

    If you are a beginner, remember the flow is as follows:

    - design the sopc system

    - when you generate it, sopc builder creates a black box block with contains the system and exposes the reuired i/o pins (i.e. clock, reset, sdram i/o, PIOs, ...)

    - add the sopc block in your Quartus project (as HDL or schematic)

    - you must connect the block pins to fpga device pins, adding glue logic if required

    - assign the used pins, based on how the actual fpga is connected to external devices (clock, sdram) on your board.

    - compile quartus project which creates the .sof configuration file

    - create the Nios bsp and application and associate it to your sopc system

    - load the fpga configuration

    - build and load the Nios application

    Regards
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Thank you again Cris,

    Sorry for late reply.

    Here is my SOPC picture.

    I have used on-chip mem, and I thought that I can use SDRAM as an on-chip mem, since I dont know where to connect this SDRAM.

    I also add some PIO pins in order to make the next LED experiment.

    Thank you,

    Yuyex :o
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Hi Yuyex,

    You MUST connect the Nios2_system sdram pins!!

    Add input or output pins like you have done for clk and LED ports. You can even use the Quartus function which automatically creates port pins: select sopc block, right click and select Generate Pins for Symbol Ports.

    You must change another thing.

    Inside sopc builder, use the same CPU_clk for sdram, too. While SDRAM_clk will be only used externally to connect to the actual sdram chip clock pin. This SDRAM_clk will need a phase shift, in order to meet timing requirements: usually a 1.5ns phase lead relative to CPU_clk is good in most situations.

    Cris
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Thank you Cris ..

    Sorry for my bagga (Japanese) =.=

    I just realize it this morning, and I have connected all of the SDRAM pin here.

    Got below message on NIOS II for creating "hello world" project :

    verifying 01000000 ( 0%)

    verify failed between address 0x1000000 and 0x100d96b

    leaving target processor paused

    The failure address is confusing me :confused:

    Thank you,

    Yuyex:o
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    Inside sopc builder, use the same CPU_clk for sdram, too. While SDRAM_clk will be only used externally to connect to the actual sdram chip clock pin.

    --- Quote End ---

    Do you mean that I cant separate the clock for CPU and the clock for SDRAM?

    I did search for this requirement and it's needed to be separated from the information I have gathered :confused:

    --- Quote Start ---

    This SDRAM_clk will need a phase shift, in order to meet timing requirements: usually a 1.5ns phase lead relative to CPU_clk is good in most situations.

    --- Quote End ---

    I made a calculation based on the formula on the user guide, which lead to -1.46 ... and do you mean minus 1.5ns?

    Thank you,

    Yuyex:o
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    Do you mean that I cant separate the clock for CPU and the clock for SDRAM?

    --- Quote End ---

    You can use a separate clock for sdram with same or different frequency.

    I meant you however need a separate clock for driving the external sdram clock pin, because you must apply the phase shift.

    So, in a general case you have 3 clocks:

    - cpu_clk

    - sdram_clk, connected to sdram controller inside sopc builder

    - sdram_ext_clk, same freq as sdram_clk but -1.5ns phase shifted; this only connects outside to sdram clk pin.

    --- Quote Start ---

    I made a calculation based on the formula on the user guide, which lead to -1.46 ... and do you mean minus 1.5ns?

    --- Quote End ---

    Yes. Minus means a phase lead as I told you.

    So my -1.5 guess was good!
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Thank you for your reply, Cris :o

    I did as you suggested me.. I have made 3 different clocks :

    1. 50MHz for CPU_clk

    2. 50MHz with -1.46 phase shift for SDRAM_clk in the SOPC

    3. 50MHZ for SDRAM_clk_ext and connects it to DE0's SDRAM clk (PIN_E5)

    I got below error :

    verifying 00800000 ( 0%)

    verify failed between address 0x800000 and 0x8002f3

    leaving target processor paused

    FYI, I did an experiment with this system + on-chip memory , and it works.

    It really seems like my SDRAM or PLL doesn't work well, but i dont know what's wrong :eek:

    Thank you,

    Yuyex:o