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Hello everyone,
I've been trying to understand the workings of the timing analyser recently. I need to implement an SDRAM Controller with Uniphy in my design. So I opened up an example project called "SoCKit_DDR3_Nios_Test. I noticed it is very similar to mine, it has a nios processor, onchip mem, clock, and so on. After compiling and constraining the I received a setup violation error. I don't know what is wrong with my constraint. I doubt I need to use set_input_delay or set_output_delay, since the sdc file doesn't even have clock groupings, which I added later on to try to repair the setup slack. The clock groupings managed to correct the negative slack on the generated clock "u0|pll_qsys|altera_pll_i|general[0].gpll~PLL_OUTPUT_COUNTER|divclk" This is my sdc file.
create_clock -period 20
create_clock -period 20
create_clock -period 20
create_clock -period 20
derive_pll_clocks
derive_clock_uncertainty
set_clock_groups -asynchronous -group {OSC_50_B3B
OSC_50_B4A
OSC_50_B5B
OSC_50_B8A
}
-group {
u0|pll_qsys|altera_pll_i|general.gpll~FRACTIONAL_PLL|vcoph
u0|pll_qsys|altera_pll_i|general.gpll~PLL_OUTPUT_COUNTER|divclk
}
-group {
u0|mem_if_ddr3_emif_fpga|DDR3_Qsys_mem_if_ddr3_emif_fpga_p0_sampling_clock
}
-group {
u0|mem_if_ddr3_emif_fpga|pll0|pll_addr_cmd_clk
u0|mem_if_ddr3_emif_fpga|pll0|pll_avl_clk
u0|mem_if_ddr3_emif_fpga|pll0|pll_dq_write_clk
u0|mem_if_ddr3_emif_fpga|pll0|pll_write_clk
}
-group {
u0|mem_if_ddr3_emif_fpga|pll0|pll_afi_clk
}
-group {
DDR3_CK_n
DDR3_CK_p
DDR3_DQS_n_OUT
DDR3_DQS_n_OUT
DDR3_DQS_n_OUT
DDR3_DQS_n_OUT
DDR3_DQS_p_IN
DDR3_DQS_p_OUT
DDR3_DQS_p_IN
DDR3_DQS_p_OUT
DDR3_DQS_p_IN
DDR3_DQS_p_OUT
DDR3_DQS_p_IN
DDR3_DQS_p_OUT
}
I can't really wrap my head around the behind-the-scene workings of Altera. Can someone please explain me? I look forward to any replies :) BTW I'm using Quartus 14.1
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I can't read your screenshot to see what paths are failing, but the IP should have generated a .sdc file for you.
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Oh I'm sorry about the screenshot
Please try this link https://imgur.com/a/yr9ldwm (https://imgur.com/a/yr9ldwm) The sdc file from the previous post was the generated sdc file. I just added the clock groups to see if that solves the failure. I added the source project folder to my attachments. This is in its original form. I would appreciate any help.
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