LF-Building-a-RISC-V-CPU-Core/risc-v_shell.tlv

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\m4_TLV_version 1d: tl-x.org
\SV
// This code can be found in: https://github.com/stevehoover/LF-Building-a-RISC-V-CPU-Core/risc-v_shell.tlv
m4_include_lib(['https://raw.githubusercontent.com/stevehoover/warp-v_includes/1d1023ccf8e7b0a8cf8e8fc4f0a823ebb61008e3/risc-v_defs.tlv'])
m4_include_lib(['https://raw.githubusercontent.com/stevehoover/LF-Building-a-RISC-V-CPU-Core/main/lib/risc-v_shell_lib.tlv'])
//---------------------------------------------------------------------------------
// /====================\
// | Sum 1 to 9 Program |
// \====================/
//
// Program to test RV32I
// Add 1,2,3,...,9 (in that order).
//
// Regs:
// x12 (a2): 10
// x13 (a3): 1..10
// x14 (a4): Sum
//
m4_asm(ADDI, x14, x0, 0) // Initialize sum register a4 with 0
m4_asm(ADDI, x12, x0, 1010) // Store count of 10 in register a2.
m4_asm(ADDI, x13, x0, 1) // Initialize loop count register a3 with 0
// Loop:
m4_asm(ADD, x14, x13, x14) // Incremental summation
m4_asm(ADDI, x13, x13, 1) // Increment loop count by 1
m4_asm(BLT, x13, x12, 1111111111000) // If a3 is less than a2, branch to label named <loop>
// Test result value in x14, and set x31 to reflect pass/fail.
m4_asm(ADDI, x30, x14, 111111010100) // Subtract expected value of 44 to set x30 to 1 if and only iff the result is 45 (1 + 2 + ... + 9).
m4_asm(BGE, x0, x0, 0) // Done. Jump to itself (infinite loop). (Up to 20-bit signed immediate plus implicit 0 bit (unlike JALR) provides byte address; last immediate bit should also be 0)
m4_asm_end()
m4_define(['M4_MAX_CYC'], 50)
//---------------------------------------------------------------------------------
\SV
m4_makerchip_module // (Expanded in Nav-TLV pane.)
/* verilator lint_on WIDTH */
\TLV
$reset = *reset;
// Program counter
$next_pc[31:0] = $reset ? 0 : ($pc + 4);
$pc[31:0] = >>1$next_pc;
// Instruction memory
`READONLY_MEM($pc, $$instr[31:0]);
// Decode instruction types
$is_u_instr = $instr[6:2] ==? 5'b0x101;
$is_i_instr = $instr[6:2] ==? 5'b0000x
|| $instr[6:2] ==? 5'b001x0
|| $instr[6:2] == 5'b11001;
$is_r_instr = $instr[6:2] ==? 5'b011x0
|| $instr[6:2] == 5'b01011
|| $instr[6:2] == 5'b10100;
$is_s_instr = $instr[6:2] ==? 5'b0100x;
$is_b_instr = $instr[6:2] == 5'b11000;
$is_j_instr = $instr[6:2] == 5'b11011;
// Assert these to end simulation (before Makerchip cycle limit).
*passed = 1'b0;
*failed = *cyc_cnt > M4_MAX_CYC;
//m4+rf(32, 32, $reset, $wr_en, $wr_index[4:0], $wr_data[31:0], $rd1_en, $rd1_index[4:0], $rd1_data, $rd2_en, $rd2_index[4:0], $rd2_data)
//m4+dmem(32, 32, $reset, $addr[4:0], $wr_en, $wr_data[31:0], $rd_en, $rd_data)
m4+cpu_viz()
\SV
endmodule