[entropy_src/rtl] check cs_ack before new cs_req
The entropy_src to csrng req/ack bus follows the 4 phase req/ack protocol very closely.
By checking that the ack is deassert before a new request is made will complete the
protocol behavior.
This also allows for verification to use the proper req/ack vip model.
Signed-off-by: Mark Branstad <mark.branstad@wdc.com>
diff --git a/hw/ip/entropy_src/rtl/entropy_src_main_sm.sv b/hw/ip/entropy_src/rtl/entropy_src_main_sm.sv
index f418304..8636f84 100644
--- a/hw/ip/entropy_src/rtl/entropy_src_main_sm.sv
+++ b/hw/ip/entropy_src/rtl/entropy_src_main_sm.sv
@@ -256,7 +256,9 @@
end
end
Sha3MsgDone: begin
- state_d = Sha3Prep;
+ if (!cs_aes_halt_ack_i) begin
+ state_d = Sha3Prep;
+ end
end
Sha3Prep: begin
// for normal or halt cases, always prevent a power spike
