<!--
  Low-cost homogeneous FPGA Architecture.

  - Skywater 130 nm technology
  - General purpose logic block:
    K = 4, N = 8, fracturable 4 LUTs (can operate as one 4-LUT or two 3-LUTs with all 3 inputs shared)
    with optionally registered outputs
  - Routing architecture:
      - 10% L = 1, fc_in = 0.15, Fc_out = 0.10
      - 10% L = 2, fc_in = 0.15, Fc_out = 0.10
      - 80% L = 4, fc_in = 0.15, Fc_out = 0.10
      - 100 routing tracks per channel

  Authors: Xifan Tang
-->
<architecture>
  <!--
       ODIN II specific config begins
       Describes the types of user-specified netlist blocks (in blif, this corresponds to
       ".model [type_of_block]") that this architecture supports.

       Note: Basic LUTs, I/Os, and flip-flops are not included here as there are
       already special structures in blif (.names, .input, .output, and .latch)
       that describe them.
  -->
  <models>
    <!-- A virtual model for I/O to be used in the physical mode of io block -->
    <model name="io">
      <input_ports>
        <port name="outpad"/>
      </input_ports>
      <output_ports>
        <port name="inpad"/>
      </output_ports>
    </model>

    <model name="frac_lut4">
      <input_ports>
        <port name="in"/>
      </input_ports>
      <output_ports>
        <port name="lut2_out"/>
        <port name="lut3_out"/>
        <port name="lut4_out"/>
      </output_ports>
    </model>
    <model name="carry_follower">
      <input_ports>
        <port name="a"/>
        <port name="b"/>
        <port name="cin"/>
      </input_ports>
      <output_ports>
        <port name="cout"/>
      </output_ports>
    </model>
    <!-- A virtual model for scan-chain flip-flop to be used in the physical mode of FF -->
    <model name="scff">
      <input_ports>
        <port name="D" clock="clk"/>
        <port name="DI" clock="clk"/>
        <port name="reset" clock="clk"/>
        <port name="clk" is_clock="1"/>
      </input_ports>
      <output_ports>
        <port name="Q" clock="clk"/>
      </output_ports>
    </model>
  </models>
  <tiles>
    <!-- Do NOT add clock pins to I/O here!!! VPR does not build clock network in the way that OpenFPGA can support
         If you need to register the I/O, define clocks in the circuit models
         These clocks can be handled in back-end
     -->
    <!-- Top-side has 1 I/O per tile -->
    <tile name="io_top" capacity="1" area="0">
      <equivalent_sites>
        <site pb_type="io"/>
      </equivalent_sites>
      <input name="outpad" num_pins="1"/>
      <output name="inpad" num_pins="1"/>
      <fc in_type="frac" in_val="0.15" out_type="frac" out_val="0.10"/>
      <pinlocations pattern="custom">
        <loc side="bottom">io_top.outpad io_top.inpad</loc>
      </pinlocations>
    </tile>
    <!-- Right-side has 1 I/O per tile -->
    <tile name="io_right" capacity="1" area="0">
      <equivalent_sites>
        <site pb_type="io"/>
      </equivalent_sites>
      <input name="outpad" num_pins="1"/>
      <output name="inpad" num_pins="1"/>
      <fc in_type="frac" in_val="0.15" out_type="frac" out_val="0.10"/>
      <pinlocations pattern="custom">
        <loc side="left">io_right.outpad io_right.inpad</loc>
      </pinlocations>
    </tile>
    <!-- Bottom-side has 9 I/O per tile -->
    <tile name="io_bottom" capacity="9" area="0">
      <equivalent_sites>
        <site pb_type="io"/>
      </equivalent_sites>
      <input name="outpad" num_pins="1"/>
      <output name="inpad" num_pins="1"/>
      <fc in_type="frac" in_val="0.15" out_type="frac" out_val="0.10"/>
      <pinlocations pattern="custom">
        <loc side="top">io_bottom.outpad io_bottom.inpad</loc>
      </pinlocations>
    </tile>
    <!-- Left-side has 1 I/O per tile -->
    <tile name="io_left" capacity="1" area="0">
      <equivalent_sites>
        <site pb_type="io"/>
      </equivalent_sites>
      <input name="outpad" num_pins="1"/>
      <output name="inpad" num_pins="1"/>
      <fc in_type="frac" in_val="0.15" out_type="frac" out_val="0.10"/>
      <pinlocations pattern="custom">
        <loc side="right">io_left.outpad io_left.inpad</loc>
      </pinlocations>
    </tile>
    <!-- CLB has most pins on the top and right sides -->
    <tile name="clb" area="53894">
      <equivalent_sites>
        <site pb_type="clb"/>
      </equivalent_sites>
      <input name="I0" num_pins="2" equivalent="full"/>
      <input name="I0i" num_pins="2" equivalent="none"/>
      <input name="I1" num_pins="2" equivalent="full"/>
      <input name="I1i" num_pins="2" equivalent="none"/>
      <input name="I2" num_pins="2" equivalent="full"/>
      <input name="I2i" num_pins="2" equivalent="none"/>
      <input name="I3" num_pins="2" equivalent="full"/>
      <input name="I3i" num_pins="2" equivalent="none"/>
      <input name="I4" num_pins="2" equivalent="full"/>
      <input name="I4i" num_pins="2" equivalent="none"/>
      <input name="I5" num_pins="2" equivalent="full"/>
      <input name="I5i" num_pins="2" equivalent="none"/>
      <input name="I6" num_pins="2" equivalent="full"/>
      <input name="I6i" num_pins="2" equivalent="none"/>
      <input name="I7" num_pins="2" equivalent="full"/>
      <input name="I7i" num_pins="2" equivalent="none"/>
      <input name="reg_in" num_pins="1"/>
      <input name="sc_in" num_pins="1"/>
      <input name="cin" num_pins="1"/>
      <input name="reset" num_pins="1" is_non_clock_global="true"/>
      <output name="O" num_pins="16" equivalent="none"/>
      <output name="reg_out" num_pins="1"/>
      <output name="sc_out" num_pins="1"/>
      <output name="cout" num_pins="1"/>
      <clock name="clk" num_pins="1"/>
      <fc in_type="frac" in_val="0.15" out_type="frac" out_val="0.10">
        <fc_override port_name="reg_in" fc_type="frac" fc_val="0"/>
        <fc_override port_name="reg_out" fc_type="frac" fc_val="0"/>
        <fc_override port_name="sc_in" fc_type="frac" fc_val="0"/>
        <fc_override port_name="sc_out" fc_type="frac" fc_val="0"/>
        <fc_override port_name="cin" fc_type="frac" fc_val="0"/>
        <fc_override port_name="cout" fc_type="frac" fc_val="0"/>
        <fc_override port_name="clk" fc_type="frac" fc_val="0"/>
        <fc_override port_name="reset" fc_type="frac" fc_val="0"/>
      </fc>
      <!--pinlocations pattern="spread"/-->
      <pinlocations pattern="custom">
        <loc side="left">clb.clk clb.reset</loc>
        <loc side="top">clb.reg_in clb.sc_in clb.cin clb.O[7:0] clb.I0 clb.I0i clb.I1 clb.I1i clb.I2 clb.I2i clb.I3 clb.I3i</loc>
        <loc side="right">clb.O[15:8] clb.I4 clb.I4i clb.I5 clb.I5i clb.I6 clb.I6i clb.I7 clb.I7i</loc>
        <loc side="bottom">clb.reg_out clb.sc_out clb.cout</loc>
      </pinlocations>
    </tile>
  </tiles>
  <!-- ODIN II specific config ends -->
  <!-- Physical descriptions begin -->
  <layout tileable="true">
    <auto_layout aspect_ratio="1.0">
      <!--Perimeter of 'io' blocks with 'EMPTY' blocks at corners-->
      <row type="io_top" starty="H-1" priority="100"/>
      <row type="io_bottom" starty="0" priority="100"/>
      <col type="io_left" startx="0" priority="100"/>
      <col type="io_right" startx="W-1" priority="100"/>
      <corners type="EMPTY" priority="101"/>
      <!--Fill with 'clb'-->
      <fill type="clb" priority="10"/>
    </auto_layout>
    <fixed_layout name="2x2" width="4" height="4">
      <!--Perimeter of 'io' blocks with 'EMPTY' blocks at corners-->
      <row type="io_top" starty="H-1" priority="100"/>
      <row type="io_bottom" starty="0" priority="100"/>
      <col type="io_left" startx="0" priority="100"/>
      <col type="io_right" startx="W-1" priority="100"/>
      <corners type="EMPTY" priority="101"/>
      <!--Fill with 'clb'-->
      <fill type="clb" priority="10"/>
    </fixed_layout>
    <fixed_layout name="12x12" width="14" height="14">
      <!--Perimeter of 'io' blocks with 'EMPTY' blocks at corners-->
      <row type="io_top" starty="H-1" priority="100"/>
      <row type="io_bottom" starty="0" priority="100"/>
      <col type="io_left" startx="0" priority="100"/>
      <col type="io_right" startx="W-1" priority="100"/>
      <corners type="EMPTY" priority="101"/>
      <!--Fill with 'clb'-->
      <fill type="clb" priority="10"/>
    </fixed_layout>
  </layout>
  <device>
    <!-- VB & JL: Using Ian Kuon's transistor sizing and drive strength data for routing, at 40 nm. Ian used BPTM
			     models. We are modifying the delay values however, to include metal C and R, which allows more architecture
			     experimentation. We are also modifying the relative resistance of PMOS to be 1.8x that of NMOS
			     (vs. Ian's 3x) as 1.8x lines up with Jeff G's data from a 45 nm process (and is more typical of
			     45 nm in general). I'm upping the Rmin_nmos from Ian's just over 6k to nearly 9k, and dropping
			     RminW_pmos from 18k to 16k to hit this 1.8x ratio, while keeping the delays of buffers approximately
			     lined up with Stratix IV.
			     We are using Jeff G.'s capacitance data for 45 nm (in tech/ptm_45nm).
			     Jeff's tables list C in for transistors with widths in multiples of the minimum feature size (45 nm).
			     The minimum contactable transistor is 2.5 * 45 nm, so I need to multiply drive strength sizes in this file
	                     by 2.5x when looking up in Jeff's tables.
			     The delay values are lined up with Stratix IV, which has an architecture similar to this
			     proposed FPGA, and which is also 40 nm
			     C_ipin_cblock: input capacitance of a track buffer, which VPR assumes is a single-stage
			     4x minimum drive strength buffer. -->
    <sizing R_minW_nmos="8926" R_minW_pmos="16067"/>
    <!-- The grid_logic_tile_area below will be used for all blocks that do not explicitly set their own (non-routing)
     	  area; set to 0 since we explicitly set the area of all blocks currently in this architecture file.
	  -->
    <area grid_logic_tile_area="0"/>
    <chan_width_distr>
      <x distr="uniform" peak="1.000000"/>
      <y distr="uniform" peak="1.000000"/>
    </chan_width_distr>
    <switch_block type="wilton" fs="3" sub_type="subset" sub_fs="3"/>
    <connection_block input_switch_name="ipin_cblock"/>
  </device>
  <switchlist>
    <!-- VB: the mux_trans_size and buf_size data below is in minimum width transistor *areas*, assuming the purple
	       book area formula. This means the mux transistors are about 5x minimum drive strength.
	       We assume the first stage of the buffer is 3x min drive strength to be reasonable given the large
	       mux transistors, and this gives a reasonable stage ratio of a bit over 5x to the second stage. We assume
	       the n and p transistors in the first stage are equal-sized to lower the buffer trip point, since it's fed
	       by a pass transistor mux. We can then reverse engineer the buffer second stage to hit the specified
	       buf_size (really buffer area) - 16.2x minimum drive nmos and 1.8*16.2 = 29.2x minimum drive.
	       I then took the data from Jeff G.'s PTM modeling of 45 nm to get the Cin (gate of first stage) and Cout
	       (diff of second stage) listed below.  Jeff's models are in tech/ptm_45nm, and are in min feature multiples.
	       The minimum contactable transistor is 2.5 * 45 nm, so I need to multiply the drive strength sizes above by
	       2.5x when looking up in Jeff's tables.
	       Finally, we choose a switch delay (58 ps) that leads to length 4 wires having a delay equal to that of SIV of 126 ps.
	       This also leads to the switch being 46% of the total wire delay, which is reasonable. -->
    <switch type="mux" name="L1_mux" R="551" Cin=".77e-15" Cout="4e-15" Tdel="58e-12" mux_trans_size="2.630740" buf_size="27.645901"/>
    <switch type="mux" name="L2_mux" R="551" Cin=".77e-15" Cout="4e-15" Tdel="58e-12" mux_trans_size="2.630740" buf_size="27.645901"/>
    <switch type="mux" name="L4_mux" R="551" Cin=".77e-15" Cout="4e-15" Tdel="58e-12" mux_trans_size="2.630740" buf_size="27.645901"/>
    <!--switch ipin_cblock resistance set to yeild for 4x minimum drive strength buffer-->
    <switch type="mux" name="ipin_cblock" R="2231.5" Cout="0." Cin="1.47e-15" Tdel="7.247000e-11" mux_trans_size="1.222260" buf_size="auto"/>
  </switchlist>
  <segmentlist>
    <!--- VB & JL: using ITRS metal stack data, 96 nm half pitch wires, which are intermediate metal width/space.
			     With the 96 nm half pitch, such wires would take 60 um of height, vs. a 90 nm high (approximated as square) Stratix IV tile so this seems
			     reasonable. Using a tile length of 90 nm, corresponding to the length of a Stratix IV tile if it were square. -->
    <!-- GIVE a specific name for the segment! OpenFPGA appreciate that! -->
    <segment name="L1" freq="0.10" length="1" type="unidir" Rmetal="101" Cmetal="22.5e-15">
      <mux name="L1_mux"/>
      <sb type="pattern">1 1</sb>
      <cb type="pattern">1</cb>
    </segment>
    <segment name="L2" freq="0.10" length="2" type="unidir" Rmetal="101" Cmetal="22.5e-15">
      <mux name="L2_mux"/>
      <sb type="pattern">1 1 1</sb>
      <cb type="pattern">1 1</cb>
    </segment>
    <segment name="L4" freq="0.80" length="4" type="unidir" Rmetal="101" Cmetal="22.5e-15">
      <mux name="L4_mux"/>
      <sb type="pattern">1 1 1 1 1</sb>
      <cb type="pattern">1 1 1 1</cb>
    </segment>
  </segmentlist>
  <directlist>
    <direct name="carry_chain" from_pin="clb.cout" to_pin="clb.cin" x_offset="0" y_offset="-1" z_offset="0"/>
    <direct name="shift_register" from_pin="clb.reg_out" to_pin="clb.reg_in" x_offset="0" y_offset="-1" z_offset="0"/>
    <direct name="scan_chain" from_pin="clb.sc_out" to_pin="clb.sc_in" x_offset="0" y_offset="-1" z_offset="0"/>
  </directlist>
  <complexblocklist>
    <!-- Define input pads begin -->
    <pb_type name="io">
      <input name="outpad" num_pins="1"/>
      <output name="inpad" num_pins="1"/>
      <!-- Do NOT add clock pins to I/O here!!! VPR does not build clock network in the way that OpenFPGA can support
           If you need to register the I/O, define clocks in the circuit models
           These clocks can be handled in back-end
       -->
      <!-- A mode denotes the physical implementation of an I/O
           This mode will be not packable but is mainly used for fabric verilog generation
        -->
      <mode name="physical" disabled_in_pack="true">
        <pb_type name="iopad" blif_model=".subckt io" num_pb="1">
          <input name="outpad" num_pins="1"/>
          <output name="inpad" num_pins="1"/>
        </pb_type>
        <interconnect>
          <direct name="outpad" input="io.outpad" output="iopad.outpad">
            <delay_constant max="1.394e-11" in_port="io.outpad" out_port="iopad.outpad"/>
          </direct>
          <direct name="inpad" input="iopad.inpad" output="io.inpad">
            <delay_constant max="4.243e-11" in_port="iopad.inpad" out_port="io.inpad"/>
          </direct>
        </interconnect>
      </mode>

      <!-- IOs can operate as either inputs or outputs.
	     Delays below come from Ian Kuon. They are small, so they should be interpreted as
	     the delays to and from registers in the I/O (and generally I/Os are registered
	     today and that is when you timing analyze them.
	     -->
      <mode name="inpad">
        <pb_type name="inpad" blif_model=".input" num_pb="1">
          <output name="inpad" num_pins="1"/>
        </pb_type>
        <interconnect>
          <direct name="inpad" input="inpad.inpad" output="io.inpad">
            <delay_constant max="4.243e-11" in_port="inpad.inpad" out_port="io.inpad"/>
          </direct>
        </interconnect>
      </mode>
      <mode name="outpad">
        <pb_type name="outpad" blif_model=".output" num_pb="1">
          <input name="outpad" num_pins="1"/>
        </pb_type>
        <interconnect>
          <direct name="outpad" input="io.outpad" output="outpad.outpad">
            <delay_constant max="1.394e-11" in_port="io.outpad" out_port="outpad.outpad"/>
          </direct>
        </interconnect>
      </mode>
      <power method="ignore"/>
    </pb_type>
    <!-- Define I/O pads ends -->
    <!-- Define general purpose logic block (CLB) begin -->
    <!-- -Due to the absence of local routing,
         the 4 inputs of fracturable LUT4 are no longer equivalent,
         because the 4th input can not be switched when the dual-LUT3 modes are used.
         So pin equivalence should be applied to the first 3 inputs only
	  -->
    <pb_type name="clb">
      <input name="I0" num_pins="2" equivalent="full"/>
      <input name="I0i" num_pins="2" equivalent="none"/>
      <input name="I1" num_pins="2" equivalent="full"/>
      <input name="I1i" num_pins="2" equivalent="none"/>
      <input name="I2" num_pins="2" equivalent="full"/>
      <input name="I2i" num_pins="2" equivalent="none"/>
      <input name="I3" num_pins="2" equivalent="full"/>
      <input name="I3i" num_pins="2" equivalent="none"/>
      <input name="I4" num_pins="2" equivalent="full"/>
      <input name="I4i" num_pins="2" equivalent="none"/>
      <input name="I5" num_pins="2" equivalent="full"/>
      <input name="I5i" num_pins="2" equivalent="none"/>
      <input name="I6" num_pins="2" equivalent="full"/>
      <input name="I6i" num_pins="2" equivalent="none"/>
      <input name="I7" num_pins="2" equivalent="full"/>
      <input name="I7i" num_pins="2" equivalent="none"/>
      <input name="reg_in" num_pins="1"/>
      <input name="sc_in" num_pins="1"/>
      <input name="cin" num_pins="1"/>
      <input name="reset" num_pins="1" is_non_clock_global="true"/>
      <output name="O" num_pins="16" equivalent="none"/>
      <output name="reg_out" num_pins="1"/>
      <output name="sc_out" num_pins="1"/>
      <output name="cout" num_pins="1"/>
      <clock name="clk" num_pins="1"/>
      <!-- Describe fracturable logic element.
             Each fracturable logic element has a 6-LUT that can alternatively operate as two 5-LUTs with shared inputs.
             The outputs of the fracturable logic element can be optionally registered
        -->
      <pb_type name="fle" num_pb="8">
        <input name="in" num_pins="4"/>
        <input name="reg_in" num_pins="1"/>
        <input name="sc_in" num_pins="1"/>
        <input name="cin" num_pins="1"/>
        <input name="reset" num_pins="1"/>
        <output name="out" num_pins="2"/>
        <output name="reg_out" num_pins="1"/>
        <output name="sc_out" num_pins="1"/>
        <output name="cout" num_pins="1"/>
        <clock name="clk" num_pins="1"/>
        <!-- Physical mode definition begin (physical implementation of the fle) -->
        <mode name="physical" disabled_in_pack="true">
          <pb_type name="fabric" num_pb="1">
            <input name="in" num_pins="4"/>
            <input name="reg_in" num_pins="1"/>
            <input name="sc_in" num_pins="1"/>
            <input name="cin" num_pins="1"/>
            <input name="reset" num_pins="1"/>
            <output name="out" num_pins="2"/>
            <output name="reg_out" num_pins="1"/>
            <output name="sc_out" num_pins="1"/>
            <output name="cout" num_pins="1"/>
            <clock name="clk" num_pins="1"/>
            <pb_type name="frac_logic" num_pb="1">
              <input name="in" num_pins="4"/>
              <input name="cin" num_pins="1"/>
              <output name="out" num_pins="2"/>
              <output name="cout" num_pins="1"/>
              <!-- Define LUT -->
              <pb_type name="frac_lut4" blif_model=".subckt frac_lut4" num_pb="1">
                <input name="in" num_pins="4"/>
                <output name="lut2_out" num_pins="2"/>
                <output name="lut3_out" num_pins="2"/>
                <output name="lut4_out" num_pins="1"/>
              </pb_type>
              <pb_type name="carry_follower" blif_model=".subckt carry_follower" num_pb="1">
                <input name="a" num_pins="1"/>
                <input name="b" num_pins="1"/>
                <input name="cin" num_pins="1"/>
                <output name="cout" num_pins="1"/>
              </pb_type>
              <interconnect>
                <direct name="direct1" input="frac_logic.in[0:1]" output="frac_lut4.in[0:1]"/>
                <direct name="direct2" input="frac_logic.in[3:3]" output="frac_lut4.in[3:3]"/>
                <direct name="direct3" input="frac_logic.cin" output="carry_follower.b"/>
                <direct name="direct4" input="frac_lut4.lut2_out[1:1]" output="carry_follower.a"/>
                <direct name="direct5" input="frac_lut4.lut2_out[0:0]" output="carry_follower.cin"/>
                <direct name="direct6" input="carry_follower.cout" output="frac_logic.cout"/>
                <direct name="direct7" input="frac_lut4.lut3_out[1]" output="frac_logic.out[1]"/>
                <!-- Xifan Tang: I use out[0] because the output of lut6 in lut6 mode is wired to the out[0] -->
                <mux name="mux1" input="frac_lut4.lut4_out frac_lut4.lut3_out[0]" output="frac_logic.out[0]"/>
                <mux name="mux2" input="frac_logic.cin frac_logic.in[2:2]" output="frac_lut4.in[2:2]"/>
              </interconnect>
            </pb_type>
            <!-- Define flip-flop with scan-chain capability, DI is the scan-chain data input -->
            <pb_type name="ff" blif_model=".subckt scff" num_pb="2">
              <input name="D" num_pins="1"/>
              <input name="DI" num_pins="1"/>
              <input name="reset" num_pins="1"/>
              <output name="Q" num_pins="1"/>
              <clock name="clk" num_pins="1"/>
              <T_setup value="66e-12" port="ff.D" clock="clk"/>
              <T_setup value="66e-12" port="ff.DI" clock="clk"/>
              <T_setup value="66e-12" port="ff.reset" clock="clk"/>
              <T_clock_to_Q max="124e-12" port="ff.Q" clock="clk"/>
            </pb_type>
            <interconnect>
              <direct name="direct1" input="fabric.in" output="frac_logic.in"/>
              <direct name="direct2" input="fabric.cin" output="frac_logic.cin"/>
              <direct name="direct3" input="fabric.sc_in" output="ff[0].DI"/>
              <direct name="direct4" input="ff[0].Q" output="ff[1].DI"/>
              <direct name="direct5" input="ff[1].Q" output="fabric.sc_out"/>
              <direct name="direct6" input="ff[1].Q" output="fabric.reg_out"/>
              <direct name="direct7" input="frac_logic.cout" output="fabric.cout"/>
              <complete name="complete1" input="fabric.clk" output="ff[1:0].clk"/>
              <complete name="complete2" input="fabric.reset" output="ff[1:0].reset"/>
              <mux name="mux1" input="frac_logic.out[0:0] fabric.reg_in" output="ff[0:0].D">
                <delay_constant max="25e-12" in_port="frac_logic.out[0:0]" out_port="ff[0:0].D"/>
                <delay_constant max="45e-12" in_port="fabric.reg_in" out_port="ff[0:0].D"/>
              </mux>
              <mux name="mux2" input="frac_logic.out[1:1] ff[0:0].Q" output="ff[1:1].D">
                <delay_constant max="25e-12" in_port="frac_logic.out[1:1]" out_port="ff[1:1].D"/>
                <delay_constant max="45e-12" in_port="ff[0:0].Q" out_port="ff[1:1].D"/>
              </mux>
              <mux name="mux3" input="ff[0].Q frac_logic.out[0]" output="fabric.out[0]">
                <!-- LUT to output is faster than FF to output on a Stratix IV -->
                <delay_constant max="25e-12" in_port="frac_logic.out[0]" out_port="fabric.out[0]"/>
                <delay_constant max="45e-12" in_port="ff[0].Q" out_port="fabric.out[0]"/>
              </mux>
              <mux name="mux4" input="ff[1].Q frac_logic.out[1]" output="fabric.out[1]">
                <!-- LUT to output is faster than FF to output on a Stratix IV -->
                <delay_constant max="25e-12" in_port="frac_logic.out[1]" out_port="fabric.out[1]"/>
                <delay_constant max="45e-12" in_port="ff[1].Q" out_port="fabric.out[1]"/>
              </mux>
            </interconnect>
          </pb_type>
          <interconnect>
            <direct name="direct1" input="fle.in" output="fabric.in"/>
            <direct name="direct2" input="fle.reg_in" output="fabric.reg_in"/>
            <direct name="direct3" input="fle.sc_in" output="fabric.sc_in"/>
            <direct name="direct4" input="fle.cin" output="fabric.cin"/>
            <direct name="direct5" input="fabric.out" output="fle.out"/>
            <direct name="direct6" input="fabric.reg_out" output="fle.reg_out"/>
            <direct name="direct7" input="fabric.sc_out" output="fle.sc_out"/>
            <direct name="direct8" input="fabric.cout" output="fle.cout"/>
            <direct name="direct9" input="fle.clk" output="fabric.clk"/>
            <direct name="direct10" input="fle.reset" output="fabric.reset"/>
          </interconnect>
        </mode>
        <!-- Physical mode definition end (physical implementation of the fle) -->
        <!-- Dual 3-LUT mode definition begin -->
        <mode name="n2_lut3">
          <pb_type name="lut3inter" num_pb="1">
            <input name="in" num_pins="3"/>
            <output name="out" num_pins="2"/>
            <clock name="clk" num_pins="1"/>
            <pb_type name="ble3" num_pb="2">
              <input name="in" num_pins="3"/>
              <output name="out" num_pins="1"/>
              <clock name="clk" num_pins="1"/>
              <!-- Define the LUT -->
              <pb_type name="lut3" blif_model=".names" num_pb="1" class="lut">
                <input name="in" num_pins="3" port_class="lut_in"/>
                <output name="out" num_pins="1" port_class="lut_out"/>
                <!-- LUT timing using delay matrix -->
                <!-- These are the physical delay inputs on a Stratix IV LUT but because VPR cannot do LUT rebalancing,
                           we instead take the average of these numbers to get more stable results
                      82e-12
                      173e-12
                      261e-12
                      263e-12
                      398e-12
                      -->
                <delay_matrix type="max" in_port="lut3.in" out_port="lut3.out">
                  235e-12
                  235e-12
                  235e-12
                </delay_matrix>
              </pb_type>
              <!-- Define the flip-flop -->
              <pb_type name="ff" blif_model=".latch" num_pb="1" class="flipflop">
                <input name="D" num_pins="1" port_class="D"/>
                <output name="Q" num_pins="1" port_class="Q"/>
                <clock name="clk" num_pins="1" port_class="clock"/>
                <T_setup value="66e-12" port="ff.D" clock="clk"/>
                <T_clock_to_Q max="124e-12" port="ff.Q" clock="clk"/>
              </pb_type>
              <interconnect>
                <direct name="direct1" input="ble3.in[2:0]" output="lut3[0:0].in[2:0]"/>
                <direct name="direct2" input="lut3[0:0].out" output="ff[0:0].D">
                  <!-- Advanced user option that tells CAD tool to find LUT+FF pairs in netlist -->
                  <pack_pattern name="ble3" in_port="lut3[0:0].out" out_port="ff[0:0].D"/>
                </direct>
                <direct name="direct3" input="ble3.clk" output="ff[0:0].clk"/>
                <mux name="mux1" input="ff[0:0].Q lut3.out[0:0]" output="ble3.out[0:0]">
                  <!-- LUT to output is faster than FF to output on a Stratix IV -->
                  <delay_constant max="25e-12" in_port="lut3.out[0:0]" out_port="ble3.out[0:0]"/>
                  <delay_constant max="45e-12" in_port="ff[0:0].Q" out_port="ble3.out[0:0]"/>
                </mux>
              </interconnect>
            </pb_type>
            <interconnect>
              <direct name="direct1" input="lut3inter.in" output="ble3[0:0].in"/>
              <direct name="direct2" input="lut3inter.in" output="ble3[1:1].in"/>
              <direct name="direct3" input="ble3[1:0].out" output="lut3inter.out"/>
              <complete name="complete1" input="lut3inter.clk" output="ble3[1:0].clk"/>
            </interconnect>
          </pb_type>
          <interconnect>
            <direct name="direct1" input="fle.in[2:0]" output="lut3inter.in"/>
            <direct name="direct2" input="lut3inter.out" output="fle.out"/>
            <direct name="direct3" input="fle.clk" output="lut3inter.clk"/>
          </interconnect>
        </mode>
        <!-- Dual 3-LUT mode definition end -->
        <!-- 4-LUT mode definition begin -->
        <mode name="n1_lut4">
          <!-- Define 4-LUT mode -->
          <pb_type name="ble4" num_pb="1">
            <input name="in" num_pins="4"/>
            <output name="out" num_pins="1"/>
            <clock name="clk" num_pins="1"/>
            <!-- Define LUT -->
            <pb_type name="lut4" blif_model=".names" num_pb="1" class="lut">
              <input name="in" num_pins="4" port_class="lut_in"/>
              <output name="out" num_pins="1" port_class="lut_out"/>
              <!-- LUT timing using delay matrix -->
              <!-- These are the physical delay inputs on a Stratix IV LUT but because VPR cannot do LUT rebalancing,
                       we instead take the average of these numbers to get more stable results
                  82e-12
                  173e-12
                  261e-12
                  263e-12
                  398e-12
                  397e-12
                  -->
              <delay_matrix type="max" in_port="lut4.in" out_port="lut4.out">
                261e-12
                261e-12
                261e-12
                261e-12
              </delay_matrix>
            </pb_type>
            <!-- Define flip-flop -->
            <pb_type name="ff" blif_model=".latch" num_pb="1" class="flipflop">
              <input name="D" num_pins="1" port_class="D"/>
              <output name="Q" num_pins="1" port_class="Q"/>
              <clock name="clk" num_pins="1" port_class="clock"/>
              <T_setup value="66e-12" port="ff.D" clock="clk"/>
              <T_clock_to_Q max="124e-12" port="ff.Q" clock="clk"/>
            </pb_type>
            <interconnect>
              <direct name="direct1" input="ble4.in" output="lut4[0:0].in"/>
              <direct name="direct2" input="lut4.out" output="ff.D">
                <!-- Advanced user option that tells CAD tool to find LUT+FF pairs in netlist -->
                <pack_pattern name="ble4" in_port="lut4.out" out_port="ff.D"/>
              </direct>
              <direct name="direct3" input="ble4.clk" output="ff.clk"/>
              <mux name="mux1" input="ff.Q lut4.out" output="ble4.out">
                <!-- LUT to output is faster than FF to output on a Stratix IV -->
                <delay_constant max="25e-12" in_port="lut4.out" out_port="ble4.out"/>
                <delay_constant max="45e-12" in_port="ff.Q" out_port="ble4.out"/>
              </mux>
            </interconnect>
          </pb_type>
          <interconnect>
            <direct name="direct1" input="fle.in" output="ble4.in"/>
            <direct name="direct2" input="ble4.out" output="fle.out[0:0]"/>
            <direct name="direct3" input="fle.clk" output="ble4.clk"/>
          </interconnect>
        </mode>
        <!-- 4-LUT mode definition end -->
        <!-- Define shift register begin -->
        <mode name="shift_register">
          <pb_type name="shift_reg" num_pb="1">
            <input name="reg_in" num_pins="1"/>
            <output name="ff_out" num_pins="2"/>
            <output name="reg_out" num_pins="1"/>
            <clock name="clk" num_pins="1"/>
            <pb_type name="ff" blif_model=".latch" num_pb="2" class="flipflop">
              <input name="D" num_pins="1" port_class="D"/>
              <output name="Q" num_pins="1" port_class="Q"/>
              <clock name="clk" num_pins="1" port_class="clock"/>
              <T_setup value="66e-12" port="ff.D" clock="clk"/>
              <T_clock_to_Q max="124e-12" port="ff.Q" clock="clk"/>
            </pb_type>
            <interconnect>
              <direct name="direct1" input="shift_reg.reg_in" output="ff[0].D"/>
              <direct name="direct2" input="ff[0].Q" output="ff[1].D"/>
              <direct name="direct3" input="ff[1].Q" output="shift_reg.reg_out"/>
              <direct name="direct4" input="ff[0].Q" output="shift_reg.ff_out[0:0]"/>
              <direct name="direct5" input="ff[1].Q" output="shift_reg.ff_out[1:1]"/>
              <complete name="complete1" input="shift_reg.clk" output="ff.clk"/>
            </interconnect>
          </pb_type>
          <interconnect>
            <direct name="direct1" input="fle.reg_in" output="shift_reg.reg_in"/>
            <direct name="direct2" input="shift_reg.reg_out" output="fle.reg_out"/>
            <direct name="direct3" input="shift_reg.ff_out" output="fle.out"/>
            <direct name="direct4" input="fle.clk" output="shift_reg.clk"/>
          </interconnect>
        </mode>
        <!-- Define shift register end -->
      </pb_type>
      <interconnect>
        <!-- We use direct connections to reduce the area to the most
             The global local routing is going to compensate the loss in routability
          -->
        <!-- FIXME: The implicit port definition results in I0[0] connected to
                    in[2]. Such twisted connection is not expected.
                    I[0] should be connected to in[0]
          -->
        <direct name="direct_fle0" input="clb.I0[0:1]" output="fle[0:0].in[0:1]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle0i" input="clb.I0i[0:1]" output="fle[0:0].in[2:3]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle1" input="clb.I1[0:1]" output="fle[1:1].in[0:1]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle1i" input="clb.I1i[0:1]" output="fle[1:1].in[2:3]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle2" input="clb.I2[0:1]" output="fle[2:2].in[0:1]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle2i" input="clb.I2i[0:1]" output="fle[2:2].in[2:3]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle3" input="clb.I3[0:1]" output="fle[3:3].in[0:1]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle3i" input="clb.I3i[0:1]" output="fle[3:3].in[2:3]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle4" input="clb.I4[0:1]" output="fle[4:4].in[0:1]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle4i" input="clb.I4i[0:1]" output="fle[4:4].in[2:3]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle5" input="clb.I5[0:1]" output="fle[5:5].in[0:1]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle5i" input="clb.I5i[0:1]" output="fle[5:5].in[2:3]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle6" input="clb.I6[0:1]" output="fle[6:6].in[0:1]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle6i" input="clb.I6i[0:1]" output="fle[6:6].in[2:3]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle7" input="clb.I7[0:1]" output="fle[7:7].in[0:1]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <direct name="direct_fle7i" input="clb.I7i[0:1]" output="fle[7:7].in[2:3]">
          <!-- TODO: Timing should be backannotated from post-PnR results -->
        </direct>
        <complete name="clks" input="clb.clk" output="fle[7:0].clk">
        </complete>
        <complete name="resets" input="clb.reset" output="fle[7:0].reset">
        </complete>
        <!-- This way of specifying direct connection to clb outputs is important because this architecture uses automatic spreading of opins.
               By grouping to output pins in this fashion, if a logic block is completely filled by 6-LUTs,
               then the outputs those 6-LUTs take get evenly distributed across all four sides of the CLB instead of clumped on two sides (which is what happens with a more
               naive specification).
          -->
        <direct name="clbouts1" input="fle[3:0].out[0:1]" output="clb.O[7:0]"/>
        <direct name="clbouts2" input="fle[7:4].out[0:1]" output="clb.O[15:8]"/>
        <!-- Shift register chain links -->
        <direct name="shift_register_in" input="clb.reg_in" output="fle[0:0].reg_in">
          <!-- Put all inter-block carry chain delay on this one edge -->
          <delay_constant max="0.16e-9" in_port="clb.reg_in" out_port="fle[0:0].reg_in"/>
          <!--pack_pattern name="chain" in_port="clb.reg_in" out_port="fle[0:0].reg_in"/-->
        </direct>
        <direct name="shift_register_out" input="fle[7:7].reg_out" output="clb.reg_out">
          <!--pack_pattern name="chain" in_port="fle[7:7].reg_out" out_port="clb.reg_out"/-->
        </direct>
        <direct name="shift_register_link" input="fle[6:0].reg_out" output="fle[7:1].reg_in">
          <!--pack_pattern name="chain" in_port="fle[6:0].reg_out" out_port="fle[7:1].reg_in"/-->
        </direct>
        <!-- Scan chain links -->
        <direct name="scan_chain_in" input="clb.sc_in" output="fle[0:0].sc_in">
          <!-- Put all inter-block carry chain delay on this one edge -->
          <delay_constant max="0.16e-9" in_port="clb.sc_in" out_port="fle[0:0].sc_in"/>
        </direct>
        <direct name="scan_chain_out" input="fle[7:7].sc_out" output="clb.sc_out">
        </direct>
        <direct name="scan_chain_link" input="fle[6:0].sc_out" output="fle[7:1].sc_in">
        </direct>
        <!-- Carry chain links -->
        <direct name="carry_chain_in" input="clb.cin" output="fle[0:0].cin">
          <!-- Put all inter-block carry chain delay on this one edge -->
          <delay_constant max="0.16e-9" in_port="clb.cin" out_port="fle[0:0].cin"/>
        </direct>
        <direct name="carry_chain_out" input="fle[7:7].cout" output="clb.cout">
        </direct>
        <direct name="carry_chain_link" input="fle[6:0].cout" output="fle[7:1].cin">
        </direct>
      </interconnect>
      <!-- Every input pin is driven by 15% of the tracks in a channel, every output pin is driven by 10% of the tracks in a channel -->
      <!-- Place this general purpose logic block in any unspecified column -->
    </pb_type>
    <!-- Define general purpose logic block (CLB) ends -->
  </complexblocklist>
</architecture>