1. LCSL Logic Circuit Simulation Language Bogdan Caprita Julian Maller Sachin Nene Chaue Shen

2. Verilog - Hardware design language (HDL) - Introduced in 1985 - Main HDL along with VHDL - Implement VLSI Circuits - Design simulation

3. Fundamentals - Based on Confluence language - More abstraction - Functional Language - Writes comparable Verilog code

4. Why use LCSL over Verilog? -Less verbose -Easier to understand -Recursion!

5. Implementation - Design circuit(s) in LCSL - Use Verilog code for simulation, synthesis

6. LCSL is simpler Xor <- comp +A +B -X X <- A '^' B end Sys <- {Xor} {VectorInput, "In1" 1 4, Sys.A} {VectorInput, "In2" 2 4, Sys.B} {VectorOutput, "Out" 3 Sys.X} {Set, "BuildName" "Xor"}

7. Verilog Counterpart module OneBitXor (In1_i, In2_i, Out_o); input [3:0] In1_i; input [3:0] In2_i; output [3:0] Out_o; wire [3:0] n1; assign n1 = In1_i ^ In2_i; assign Out_o = n1; endmodule

8. Back to example Xor <- comp +A +B -X X <- A '^' B end Sys <- {Xor} {VectorInput, "In1" 1 4, Sys.A} {VectorInput, "In2" 2 4, Sys.B} {VectorOutput, "Out" 3 Sys.X} {Set, "BuildName" "OneBitXor"}

9. Circuit implemented

10. Functional Programming  Lambda functions  Beta reductions  “Variables”  Recursion  Evaluation λ

11. Another example Xor <- comp +A +B -X X <- A '^' B end BusXor <- comp +A +B -X if width A == 0 X <- '' else {Xor, 'lsb' A 'lsb' B, BitX} {BusXor, 'msbs' A 'msbs' B, SubX} X <- SubX '++' BitX end

12. Another example (Cont’d) Sys <- {BusXor} {VectorInput, "In1" 1 4, Sys.A} {VectorInput, "In2" 2 4, Sys.B} {VectorOutput, "Out" 3 Sys.X} {Set, "BuildName" "NBitXor"}

13. Circuit implemented

14. And the Verilog for it module NBitXor (In1_i, In2_i, Out_o); input [3:0] In1_i; input [3:0] In2_i; output [3:0] Out_o; wire [3:0] n1; NBitXor_1 s1 (In1_i, In2_i, n1); assign Out_o = n1; endmodule module NBitXor_1 (i1, i2, o1); input [3:0] i1; input [3:0] i2; output [3:0] o1; wire n1; wire [2:0] n2; wire n3; wire [1:0] n4 wire n5; wire n6; wire n7; wire n8; wire n9; wire [2:0] n10; wire n11; wire n12; wire [1:0] n13; wire n14; wire n15; wire n16;

15. And the Verilog for it (Cont’d) wire n17; wire n18; wire [1:0] n19; wire [2:0] n20; wire [3:0] n21; assign n1 = i1[0]; assign n2 = {i1[3], i1[2], i1[1]}; assign n3 = n2[0]; assign n4 = {n2[2], n2[1]}; assign n5 = n4[0]; assign n6 = n4[1]; assign n7 = n6; assign n8 = i2[0]; assign n9 = n1 ^ n8; assign n10 = {i2[3], i2[2], i2[1]}; assign n11 = n10[0]; assign n12 = n3 ^ n11; assign n13 = {n10[2], n10[1]}; assign n14 = n13[0]; assign n15 = n5 ^ n14; assign n16 = n13[1]; assign n17 = n16; assign n18 = n7 ^ n17; assign n19 = {n18, n15}; assign n20 = {n19, n12}; assign n21 = {n20, n9}; assign o1 = n21; endmodule

16. Lessons learned  Separation of tasks more efficient  Managing/organizing code  Intermediate deadlines  Teamwork/Communication