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Initial HERV implementation

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This commit is contained in:
Olof Kindgren
2025-05-14 01:42:41 +02:00
parent 15bf53241b
commit 1a8434b7ab
9 changed files with 248 additions and 17 deletions
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13
rtl/serv_ctrl.v
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@@ -55,7 +55,7 @@ module serv_ctrl
generate
if (W == 1) begin : gen_plus_4_w_eq_1
assign plus_4 = i_iscomp ? i_cnt1 : i_cnt2;
end else if (W == 4) begin : gen_plus_4_w_eq_4
end else if (W >= 4) begin : gen_plus_4_w_ge_4
assign plus_4 = (i_cnt0 | i_cnt1) ? (i_iscomp ? 2 : 4) : 0;
end
endgenerate
@@ -70,6 +70,8 @@ module serv_ctrl
assign new_pc = i_trap ? (i_csr_pc & !(i_cnt0 || i_cnt1)) : i_jump ? pc_plus_offset_aligned : pc_plus_4;
end else if (W == 4) begin : gen_new_pc_w_eq_4
assign new_pc = i_trap ? (i_csr_pc & ((i_cnt0 || i_cnt1) ? 4'b1100 : 4'b1111)) : i_jump ? pc_plus_offset_aligned : pc_plus_4;
end else if (W == 8) begin : gen_new_pc_w_eq_8
assign new_pc = i_trap ? (i_csr_pc & ((i_cnt0 || i_cnt1) ? 8'b11111100 : 8'b11111111)) : i_jump ? pc_plus_offset_aligned : pc_plus_4;
end
end else begin : gen_no_csr
assign new_pc = i_jump ? pc_plus_offset_aligned : pc_plus_4;
@@ -78,7 +80,14 @@ module serv_ctrl
assign o_rd = ({W{i_utype}} & pc_plus_offset_aligned) | (pc_plus_4 & {W{i_jal_or_jalr}});
assign offset_a = {W{i_pc_rel}} & pc;
assign offset_b = i_utype ? (i_imm & {W{i_cnt12to15 | i_cnt16to31}}) : i_buf;
generate
if (W == 8) begin : gen_offset_w_eq_8
assign offset_b = i_utype ? (i_imm & {{4{i_cnt12to15 | i_cnt16to31}}, {4{i_cnt16to31}}}) : i_buf;
end else begin : gen_offset_w_lt_8
assign offset_b = i_utype ? (i_imm & {W{i_cnt12to15 | i_cnt16to31}}) : i_buf;
end
endgenerate
assign {pc_plus_offset_cy,pc_plus_offset} = offset_a+offset_b+pc_plus_offset_cy_r_w;
generate