wiki:FC7_Log

Version 20 (modified by Eric Hazen, 6 years ago) (diff)

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2017-03-30 (hazen)

N.B. design is on watt in ~/ISE/fc7. IPbus is an older version in ~/ISE/cactus. Using Vivado 2015.2.

IP address mysteries. In system_core.vhd, find:

  generic map (mac_cfg => internal, ip_cfg  => internal, n_oob => 1) 

Change both to external and recompile. Now the IP address is the expected constant one, 192.168.1.80. So in principle this is understood now.

2016-06-07 (hazen)

Try to bring out some signals to the test connector (P4). Here are current assignments:

P4 Pin Schematic Signal
1 Voltage
2 GND
3 FMC_L12_SPARE00 ctrl_reg(0)(0)
4 FMC_L12_SPARE01 ctrl_reg(0)(1)
5 FMC_L12_SPARE02 fabric_clk
6 FMC_L12_SPARE03 tts_aligned
7 FMC_L12_SPARE04 0
8 FMC_L12_SPARE05 1
9 FMC_L12_SPARE06 0
10 FMC_L12_SPARE07 1

It seems these are commented out in sys.xdc and fc7_top.vhd. Uncomment them and put some signals on them as above. All good, signals expected appear on header.

2016-06-01 (hazen)

Add a bufg in the ref_clock to idelay_clk_i to tts_rx and set idelayctrl_gen back to true. Now it builds (?!). But does it work?

2016-05-30 (hazen)

  • Re-generate 400Mhz PLL with reset, locked
    • usr_led2 is bits (23:21) of 40Mhz counter
    • stat_reg 0x40000006 bit 0 is 'locked'
    • ctrl_reg 0x40000041 bit 0 is 'reset'

Doesn't meet timing at 400MHz, but OK at 250MHz.

Create 5X TTC clock as needed by TTS tx. ("ttc_clk_x5" using DCM this time). Same signals as above. Source is fabric_clk.

fabric_clk input constraint specified 24ns period, while PLL input was 25ns. This caused timing to fail. Couldn't figure out how to specify a 24ns period for the PLL, so changed the input constraint to 25ns for now. *Fail*.

Comment out clock constraints in PLL (ttc_clk_x5_v3.xdc). Input constraint should propagate? Now it works.

Looking to add TTS Tx with output connected to SFP on FMC. Schematic for FMC:

https://edms.cern.ch/ui/file/1350700/1/EDA-02707-V2-0_sch.pdf][EDA-02707-V2-0_sch.pdf

Add tts_tx plus other required stuff. ctrl_reg 0x40000042 is output data for TTS tx. Fix UCF lines to eliminate logic type for SFP outputs.

Integrated tts_rx. Fails timing. Problem net seems to be the ref_clk for the idelayctrl which is an idelayctrl instantiated at the bottom of serdes_rx_custom.vhd. This is required according to the docs when the IDELAYE2 is set with IDELAY_TYPE="VAR_LOAD" as in serdes_rx_custom.vhd.

With idelayctrl_gen=false in user_logic_basic (instantiate tts_rx) then the design builds, but violates the above rule so probably won't work. Need some more study.

2016-05-27 (hazen)

Measure two available clocks in user logic:

  • ipb_clk is about 32MHz
  • fabric_clk is about 40.1 MHz (maybe the LHC freq?)

Actually ipb_clk is 31.25MHz, generated using a PLL from 125MHz crystal

In ...fw/src/sys/ipb_fc7/clocks_7s_serdes_fc7.vhd an entity syspll which is a DCM is instantiated, which just converts 125MHz to 31.25MHz. It's buffered with a bufg in the PLL.

With some minor effort, create a PLL to generate 400MHz from 31.25MHz called my_clk400.

Add an instance and counter to the user logic. Register map is now:

0x40000000 - 0x676f6c64  "gold"
0x40000001 - 0x00000001
0x40000002 - firmware id
0x40000003 - ipb_clk counter (32 bits)
0x40000004 - fabric_clk counter (32 bits)
0x40000005 - 400MHz counter divide-by-ten (32 bits)

The 400MHz isn't working. Enough for today (Friday 6pm)