[otbn] Don't flop `done_o` output from otbn_core
The `done_o` output flops into top-level register/interrupt primitives
so there's no need to flop it internally.
Signed-off-by: Greg Chadwick <gac@lowrisc.org>
diff --git a/hw/ip/otbn/rtl/otbn_controller.sv b/hw/ip/otbn/rtl/otbn_controller.sv
index 289c224..7af857e 100644
--- a/hw/ip/otbn/rtl/otbn_controller.sv
+++ b/hw/ip/otbn/rtl/otbn_controller.sv
@@ -100,9 +100,6 @@
output logic ispr_bignum_wr_en_o,
input logic [WLEN-1:0] ispr_rdata_i
);
-
- logic done_d, done_q;
-
otbn_state_e state_q, state_d;
logic stall;
@@ -158,17 +155,7 @@
assign mem_stall = lsu_load_req_o;
assign stall = mem_stall;
- assign done_d = insn_valid_i && insn_dec_shared_i.ecall_insn;
-
- always_ff @(posedge clk_i or negedge rst_ni) begin
- if (!rst_ni) begin
- done_q <= 1'b0;
- end else begin
- done_q <= done_d;
- end
- end
-
- assign done_o = done_q;
+ assign done_o = insn_valid_i && insn_dec_shared_i.ecall_insn;
// Branch taken when there is a valid branch instruction and comparison passes or a valid jump
// instruction (which is always taken)
@@ -198,7 +185,7 @@
OtbnStateRun: begin
insn_fetch_req_valid_o = 1'b1;
- if (done_d) begin
+ if (done_o) begin
state_d = OtbnStateHalt;
insn_fetch_req_valid_o = 1'b0;
end else begin
