wiki:L0MdtDaq

Code and Notes

Work Log

2022-06-20

Start writing daq_unit_tb but not finished. Push to Git.

2022-06-07

Next step is to build a simulation tb for daq_unit which contains the random generators and get it working. That way the sim can be compared with the basys3 hardware version.

2022-03-10

Working on picoblaze-ebus top-level with l0mdt-daq-felix submodule. Address table:

00000000 - GPIO/control
10000000 - rate meter for test     \ these are connected together

  0 - rate generator (at 20000000)
  1 - MDT trigger rate
  2 - MDT hit rate
  3 - N/A

20000000 - rate generator for test / for basic checking, unrelated to L0MDT
30000000 - FELIX readout

GPIO:

Control regs
  0 - trigger rate random threshold [1]
  1 - hit rate random threshold [2]
  2 - n/a
  3 - n/a

Status regs
  4 - switches
  5 - n/a

Action regs
100 - 
      bit 1:  OcR
      bit 2:  EcR

Soft reset: output to 10, so command "O 10 0"

FELIX:

  Address    Read              Write      Notes
  0..7       Data              N/A        32-bit chunks, low-endian
  8          "beef" + wr_addr  wr_addr    10 bits
  9          "cafe" + rd_addr  rd_addr    10 bits
  A          wr_ena            wr_ena     bit 0 only

[1] - <value>/2**32 is probability of trigger in one BX
[2] - <value>/2**32 is probability of tube hit in one clock

Clock period is 100MHz for testing, BX period is 1/8 of that or 1/12.5MHz

2022-02-13

Andrew says to ignore ttc-core submodule.

Need to figure out where to put in the TTC generator. Currently there is a ttc_commands record originating in top_hal.vhd originating in felix_decoder. So for now we should make a ttc_commands record which is of type l0mdt_ttc_rt.

  subtype bcid_t is unsigned(12-1 downto 0);
  subtype evid_t is unsigned(32-1 downto 0);
  subtype orid_t is unsigned(32-1 downto 0);

 type l0mdt_ttc_rt is record
    bcr : std_logic;
    ocr : std_logic;
    ecr : std_logic;
    l0a : std_logic;
    l1a : std_logic;
    bcid : bcid_t;
    evid : evid_t;
    orid : orid_t;
  end record l0mdt_ttc_rt;

Looking at the clocking. In top_clocking there is framework_mmcm which outputs clk320 and clk40. There's a record l0mdt_control_rt as:

  type l0mdt_control_rt is record
    clk : std_logic;
    rst : std_logic;
    bx : std_logic;
  end record l0mdt_control_rt;

The strobe bx is generated by an instance of clock_strobe in top_hal.vhd.

2022-02-07

Working on random hit/trig generator. VHDL entity trig_gen.vhd generates random triggers at specified rate. Currently it generates one urand per clock at 100MHz, which requires two DSP48 in an Artix-7. Basys3 test project created and tested.

Also working on synthesizable ttc_eric.vhd which generates global TTC signals, including a map of LHC bunch structure.

Thinking about generating some semi-legit looking random MDT data. Here's the data format as of now:

- tdcpolmux2tar:
  - data_valid:  [type : logic]
  - tdc:  [type : tdc]                                               #  1
    - chanid:  [type : unsigned , length : TDC_CHANID_LEN]           #  5   
    - edgemode:  [type : logic , length : TDC_EDGEMODE_LEN]          #  2   
    - coarsetime:  [type : unsigned , length : TDC_COARSETIME_LEN]   # 12  
    - finetime:  [type : unsigned , length : TDC_FINETIME_LEN]       #  5  
    - pulsewidth:  [type : unsigned , length : TDC_PULSEWIDTH_LEN]   #  8   
  - csmid:  [type : unsigned , length : TDCPOLMUX2TAR_CSMID_LEN]     #  4
  - tdcid:  [type : unsigned , length : TDCPOLMUX2TAR_TDCID_LEN]     #  5

2022-01-21

Thoughts on HW testing: Create a programmable random trigger/hit generator and simple control interface (picoblaze?) Build for some eval board or even a CM and test.

2022-01-17

Seems to be working, with a few caveats. For an 80MHz hit rate, 1MHz trigger rate, 32 WM. Compare against output of simulation check_daq.pl. There are a few errors; all seem to be off-by-one at the extreme end of the matching window. Not sure this is that important.

2022-01-11

First version synthesized. No constraints. 32 WM. Utilization:

https://ohm.bu.edu/~hazen/ATLAS/Phase2MDT/daq-synth1.jpg

This compares favorably with blackboard estimate! I've created a constraint file and trying to build with 320MHz clock now.

2022-01-07

Working on "toy" DAQ for resource comparison. Here's a detailed specification :)

https://ohm.bu.edu/~hazen/ATLAS/Phase2MDT/daq-blackboard.jpg

Assumptions:

  • One pipeline hit stream stream (aka PTSD) at ~320MHz feeds one FELIX fiber.
  • Each "DAQ block" handles one such stream/fiber and operates independently of all others
  • Inputs:
    • TTC: clock, trigger, BX strobe, BcN[11:0], OrN[11:0], EvN[11:0]
    • HITS: 41 bits data (with BcN at known bit offset) and data valid
  • Outputs:
    • 230 bit FELIX data at pipeline clock, data valid
  • Monitoring
    • Various random error signals come out and could be connected somewhere

Given the first assumption the DAQ is conceptually very simple. Here are the VHDL entities:

wm
single window match with FIFO
dispatch
group of window matchers. Dispatcher for triggers, mux for output
format
output formatter. Currently includes trigger FIFO. Outputs header, data, trailer words to FELIX with a few hits packed in each data word.
daq
top level, includes one dispatch and one format.

'2021-12-15

Investigating PicoBlaze? speed... if one would run at 320MHz it could be a useful tool for DAQ work. Creating a simple test design in a xcvu3p-ffvc1517-1-i device. Just the picoblaze, very short program, and 4 each input and output ports decoded with 1 address bit per port.

Configured with 100MHz clock input, MMCM synthesizing 320MHz. Seems to have worked. Trying 400MHz. Nope. For 320MHz the reported WNS is 0.095ns. Ouch!

2021-12-01

Looking at the DAQ.

The submodule with the code is here: https://gitlab.cern.ch/tcpaiva/atlas-daq-core

It is included here: https://gitlab.cern.ch/atlas-tdaq-phase2-l0mdt-electronics/l0mdt-hdl-design/-/tree/devel/UserLogic/daq

Here is the hierarchy resulting from loading all the VHDL files into Vivado:

https://ohm.bu.edu/~hazen/ATLAS/Phase2MDT/DAQ_h.png

Top level is at UserLogic/ult/src/ult_daq.vhd. Entity daq takes as input arrays for each station (I, M, O, X) an mdt_polmux_bus_avt which consists of tdcpolmux2tar_rt which have csmid, tdcid and tdc_rt.

- tdcpolmux2tar:
  - data_valid:  [type : logic]
  - tdc:  [type : tdc]                                               #  1
    - chanid:  [type : unsigned , length : TDC_CHANID_LEN]           #  5
    - edgemode:  [type : logic , length : TDC_EDGEMODE_LEN]          #  2
    - coarsetime:  [type : unsigned , length : TDC_COARSETIME_LEN]   # 12
    - finetime:  [type : unsigned , length : TDC_FINETIME_LEN]       #  5
    - pulsewidth:  [type : unsigned , length : TDC_PULSEWIDTH_LEN]   #  8
  - csmid:  [type : unsigned , length : TDCPOLMUX2TAR_CSMID_LEN]     #  4
  - tdcid:  [type : unsigned , length : TDCPOLMUX2TAR_TDCID_LEN]     #  5
                                                               # Total 42

Here we see loops over inner_tdc_hits which is an array of 6 "streams" of input data (6x POLMUX presumably).

Output is felix_stream_bus_avt, defined in {shared/types/common_types_pkg.vhd as an array of felix_data_t plus valid. For some reason the felix_data_t is 65 bits wide.

All the mess is in daq_branch.vhd in UserLogic/daq/daq-core/src. This is very confusing code which Thiago is going to explain to us :)

Here it goes:

  in UserLogic/ult/src/ult_daq.vhd:
    daq_streams(j) <= outputify( inner_er.o.f2e_bus(j))  (inner_er is daq_branch_ert)
    daq_branch_t is array of daq_stream_rt
    daq_stream_rt is (valid, bcid, daq_stream_data_t)

I give up!

Last modified 7 weeks ago Last modified on Jun 20, 2022, 4:10:57 PM