[entropy_src/rtl] field enable has only 2 value states
For a 4 bit field, logic has been added to only respond to a value of 0xa and a value of 0x5.
Signed-off-by: Mark Branstad <mark.branstad@wdc.com>
diff --git a/hw/ip/entropy_src/entropy_src.core b/hw/ip/entropy_src/entropy_src.core
index 4b95d56..5002ec7 100644
--- a/hw/ip/entropy_src/entropy_src.core
+++ b/hw/ip/entropy_src/entropy_src.core
@@ -19,6 +19,7 @@
- rtl/entropy_src_reg_pkg.sv
- rtl/entropy_src_reg_top.sv
- rtl/entropy_src_watermark_reg.sv
+ - rtl/entropy_src_field_en.sv
- rtl/entropy_src_cntr_reg.sv
- rtl/entropy_src_ack_sm.sv
- rtl/entropy_src_main_sm.sv
diff --git a/hw/ip/entropy_src/rtl/entropy_src.sv b/hw/ip/entropy_src/rtl/entropy_src.sv
index 664b47a..f0c9449 100644
--- a/hw/ip/entropy_src/rtl/entropy_src.sv
+++ b/hw/ip/entropy_src/rtl/entropy_src.sv
@@ -211,7 +211,6 @@
stub_hw2reg = '0;
// as long as enable is 1, do not allow registers to be written
- stub_hw2reg.regwen.d = ~|reg2hw.conf.enable.q;
stub_hw2reg.fw_ov_rd_data.d = stub_lfsr_value[31:0];
stub_hw2reg.entropy_data.d = stub_lfsr_value[31:0];
stub_hw2reg.debug_status.main_sm_idle.d = 1'b1;
diff --git a/hw/ip/entropy_src/rtl/entropy_src_core.sv b/hw/ip/entropy_src/rtl/entropy_src_core.sv
index 9e0a90e..647235e 100644
--- a/hw/ip/entropy_src/rtl/entropy_src_core.sv
+++ b/hw/ip/entropy_src/rtl/entropy_src_core.sv
@@ -62,8 +62,7 @@
localparam int ObserveFifoDepth = 64;
localparam int PreCondWidth = 64;
localparam int Clog2ObserveFifoDepth = $clog2(ObserveFifoDepth);
- // TODO: remove or enable below
- // localparam int FieldEnableWidth = 4;
+ localparam int FieldEnableWidth = 4;
//-----------------------
// SHA3 parameters
@@ -443,50 +442,39 @@
// set up secure enable bits
//--------------------------------------------
- // TODO: remove or enable prim_field_enable
-// prim_field_enable #(
-// .FieldW(FieldEnableWidth),
-// .FieldEnVal(int'(ES_FIELD_ON))
-// ) u_prim_field_enable_es_enable (
-// .clk_i (clk_i),
-// .rst_ni (rst_ni),
-// .wvalid_i (reg2hw.conf.enable.qe),
-// .wdata_i (reg2hw.conf.enable.q),
-// .enable_o (es_enable_pfe)
-// );
+ entropy_src_field_en #(
+ .FieldW(FieldEnableWidth),
+ .FieldEnVal(int'(ES_FIELD_ON))
+ ) u_entropy_src_field_en_es_enable (
+ .clk_i (clk_i),
+ .rst_ni (rst_ni),
+ .wvalid_i (reg2hw.conf.enable.qe),
+ .wdata_i (reg2hw.conf.enable.q),
+ .enable_o (es_enable_pfe)
+ );
- assign es_enable_pfe = (es_enb_e'(reg2hw.conf.enable.q) == ES_FIELD_ON);
+ entropy_src_field_en #(
+ .FieldW(FieldEnableWidth),
+ .FieldEnVal(int'(ES_FIELD_ON))
+ ) u_entropy_src_field_en_lfsr_enable (
+ .clk_i (clk_i),
+ .rst_ni (rst_ni),
+ .wvalid_i (reg2hw.conf.lfsr_enable.qe),
+ .wdata_i (reg2hw.conf.lfsr_enable.q),
+ .enable_o (lfsr_enable_pfe)
+ );
- // TODO: remove or enable prim_field_enable
-// prim_field_enable #(
-// .FieldW(FieldEnableWidth),
-// .FieldEnVal(int'(ES_FIELD_ON))
-// ) u_prim_field_enable_lfsr_enable (
-// .clk_i (clk_i),
-// .rst_ni (rst_ni),
-// .wvalid_i (reg2hw.conf.lfsr_enable.qe),
-// .wdata_i (reg2hw.conf.lfsr_enable.q),
-// .enable_o (lfsr_enable_pfe)
-// );
+ entropy_src_field_en #(
+ .FieldW(FieldEnableWidth),
+ .FieldEnVal(int'(ES_FIELD_ON))
+ ) u_entropy_src_field_en_entropy_data_reg_en (
+ .clk_i (clk_i),
+ .rst_ni (rst_ni),
+ .wvalid_i (reg2hw.conf.entropy_data_reg_enable.qe),
+ .wdata_i (reg2hw.conf.entropy_data_reg_enable.q),
+ .enable_o (entropy_data_reg_en_pfe)
+ );
- assign lfsr_enable_pfe = (es_enb_e'(reg2hw.conf.lfsr_enable.q) == ES_FIELD_ON);
-
- // TODO: remove or enable prim_field_enable
-// prim_field_enable #(
-// .FieldW(FieldEnableWidth),
-// .FieldEnVal(int'(ES_FIELD_ON))
-// ) u_prim_field_enable_entropy_data_reg_en (
-// .clk_i (clk_i),
-// .rst_ni (rst_ni),
-// .wvalid_i (reg2hw.conf.entropy_data_reg_enable.qe),
-// .wdata_i (reg2hw.conf.entropy_data_reg_enable.q),
-// .enable_o (entropy_data_reg_en_pfe)
-// );
-
- assign entropy_data_reg_en_pfe =
- (es_enb_e'(reg2hw.conf.entropy_data_reg_enable.q) == ES_FIELD_ON);
-
-// assign es_enable_d = reg2hw.conf.enable.q; // TODO: remove
assign es_enable_d = {lfsr_enable_pfe,es_enable_pfe};
assign es_enable_early = lfsr_enable_pfe || es_enable_pfe;
assign es_enable = (|es_enable_q);
@@ -495,34 +483,27 @@
assign load_seed = !es_enable;
assign observe_fifo_thresh = reg2hw.observe_fifo_thresh.q;
- // TODO: remove or enable prim_field_enable
-// prim_field_enable #(
-// .FieldW(FieldEnableWidth),
-// .FieldEnVal(int'(ES_FIELD_ON))
-// ) u_prim_field_enable_fw_ov_mode (
-// .clk_i (clk_i),
-// .rst_ni (rst_ni),
-// .wvalid_i (reg2hw.fw_ov_control.fw_ov_mode.qe),
-// .wdata_i (reg2hw.fw_ov_control.fw_ov_mode.q),
-// .enable_o (fw_ov_mode_pfe)
-// );
+ entropy_src_field_en #(
+ .FieldW(FieldEnableWidth),
+ .FieldEnVal(int'(ES_FIELD_ON))
+ ) u_entropy_src_field_en_fw_ov_mode (
+ .clk_i (clk_i),
+ .rst_ni (rst_ni),
+ .wvalid_i (reg2hw.fw_ov_control.fw_ov_mode.qe),
+ .wdata_i (reg2hw.fw_ov_control.fw_ov_mode.q),
+ .enable_o (fw_ov_mode_pfe)
+ );
- assign fw_ov_mode_pfe = (es_enb_e'(reg2hw.fw_ov_control.fw_ov_mode.q) == ES_FIELD_ON);
-
- // TODO: remove or enable prim_field_enable
-// prim_field_enable #(
-// .FieldW(FieldEnableWidth),
-// .FieldEnVal(int'(ES_FIELD_ON))
-// ) u_prim_field_enable_fw_ov_entropy_insert (
-// .clk_i (clk_i),
-// .rst_ni (rst_ni),
-// .wvalid_i (reg2hw.fw_ov_control.fw_ov_entropy_insert.qe),
-// .wdata_i (reg2hw.fw_ov_control.fw_ov_entropy_insert.q),
-// .enable_o (fw_ov_entropy_insert_pfe)
-// );
-
- assign fw_ov_entropy_insert_pfe =
- (es_enb_e'(reg2hw.fw_ov_control.fw_ov_entropy_insert.q) == ES_FIELD_ON);
+ entropy_src_field_en #(
+ .FieldW(FieldEnableWidth),
+ .FieldEnVal(int'(ES_FIELD_ON))
+ ) u_entropy_src_field_en_fw_ov_entropy_insert (
+ .clk_i (clk_i),
+ .rst_ni (rst_ni),
+ .wvalid_i (reg2hw.fw_ov_control.fw_ov_entropy_insert.qe),
+ .wdata_i (reg2hw.fw_ov_control.fw_ov_entropy_insert.q),
+ .enable_o (fw_ov_entropy_insert_pfe)
+ );
// firmware override controls
assign fw_ov_mode = efuse_es_sw_ov_en_i && fw_ov_mode_pfe;
@@ -793,19 +774,16 @@
// pack esrng bus into signal bit packer
- // TODO: remove or enable prim_field_enable
-// prim_field_enable #(
-// .FieldW(FieldEnableWidth),
-// .FieldEnVal(int'(ES_FIELD_ON))
-// ) u_prim_field_enable_rng_bit_en (
-// .clk_i (clk_i),
-// .rst_ni (rst_ni),
-// .wvalid_i (reg2hw.conf.rng_bit_enable.qe),
-// .wdata_i (reg2hw.conf.rng_bit_enable.q),
-// .enable_o (rng_bit_en_pfe)
-// );
-
- assign rng_bit_en_pfe = (es_enb_e'(reg2hw.conf.rng_bit_enable.q) == ES_FIELD_ON);
+ entropy_src_field_en #(
+ .FieldW(FieldEnableWidth),
+ .FieldEnVal(int'(ES_FIELD_ON))
+ ) u_entropy_src_field_en_rng_bit_en (
+ .clk_i (clk_i),
+ .rst_ni (rst_ni),
+ .wvalid_i (reg2hw.conf.rng_bit_enable.qe),
+ .wdata_i (reg2hw.conf.rng_bit_enable.q),
+ .enable_o (rng_bit_en_pfe)
+ );
assign rng_bit_en = rng_bit_en_pfe;
assign rng_bit_sel = reg2hw.conf.rng_bit_sel.q;
@@ -857,19 +835,16 @@
assign markov_active = es_enable;
assign extht_active = es_enable;
- // TODO: remove or enable prim_field_enable
-// prim_field_enable #(
-// .FieldW(FieldEnableWidth),
-// .FieldEnVal(int'(ES_FIELD_ON))
-// ) u_prim_field_enable_health_test_clr (
-// .clk_i (clk_i),
-// .rst_ni (rst_ni),
-// .wvalid_i (reg2hw.conf.health_test_clr.qe),
-// .wdata_i (reg2hw.conf.health_test_clr.q),
-// .enable_o (health_test_clr_pfe)
-// );
-
- assign health_test_clr_pfe = (es_enb_e'(reg2hw.conf.health_test_clr.q) == ES_FIELD_ON);
+ entropy_src_field_en #(
+ .FieldW(FieldEnableWidth),
+ .FieldEnVal(int'(ES_FIELD_ON))
+ ) u_entropy_src_field_en_health_test_clr (
+ .clk_i (clk_i),
+ .rst_ni (rst_ni),
+ .wvalid_i (reg2hw.conf.health_test_clr.qe),
+ .wdata_i (reg2hw.conf.health_test_clr.q),
+ .enable_o (health_test_clr_pfe)
+ );
assign health_test_clr = health_test_clr_pfe;
@@ -1240,47 +1215,38 @@
assign event_es_health_test_failed = es_main_sm_alert;
assign event_es_observe_fifo_ready = observe_fifo_thresh_met;
- // TODO: remove or enable prim_field_enable
-// prim_field_enable #(
-// .FieldW(FieldEnableWidth),
-// .FieldEnVal(int'(ES_FIELD_ON))
-// ) u_prim_field_enable_es_route (
-// .clk_i (clk_i),
-// .rst_ni (rst_ni),
-// .wvalid_i (reg2hw.entropy_control.es_route.qe),
-// .wdata_i (reg2hw.entropy_control.es_route.q),
-// .enable_o (es_route_pfe)
-// );
+ entropy_src_field_en #(
+ .FieldW(FieldEnableWidth),
+ .FieldEnVal(int'(ES_FIELD_ON))
+ ) u_entropy_src_field_en_es_route (
+ .clk_i (clk_i),
+ .rst_ni (rst_ni),
+ .wvalid_i (reg2hw.entropy_control.es_route.qe),
+ .wdata_i (reg2hw.entropy_control.es_route.q),
+ .enable_o (es_route_pfe)
+ );
- assign es_route_pfe = (es_enb_e'(reg2hw.entropy_control.es_route.q) == ES_FIELD_ON);
+ entropy_src_field_en #(
+ .FieldW(FieldEnableWidth),
+ .FieldEnVal(int'(ES_FIELD_ON))
+ ) u_entropy_src_field_en_es_type (
+ .clk_i (clk_i),
+ .rst_ni (rst_ni),
+ .wvalid_i (reg2hw.entropy_control.es_type.qe),
+ .wdata_i (reg2hw.entropy_control.es_type.q),
+ .enable_o (es_type_pfe)
+ );
- // TODO: remove or enable prim_field_enable
-// prim_field_enable #(
-// .FieldW(FieldEnableWidth),
-// .FieldEnVal(int'(ES_FIELD_ON))
-// ) u_prim_field_enable_es_type (
-// .clk_i (clk_i),
-// .rst_ni (rst_ni),
-// .wvalid_i (reg2hw.entropy_control.es_type.qe),
-// .wdata_i (reg2hw.entropy_control.es_type.q),
-// .enable_o (es_type_pfe)
-// );
-
- assign es_type_pfe = (es_enb_e'(reg2hw.entropy_control.es_type.q) == ES_FIELD_ON);
-
- // TODO: remove or enable prim_field_enable
-// prim_field_enable #(
-// .FieldW(FieldEnableWidth),
-// .FieldEnVal(int'(ES_FIELD_ON))
-// ) u_prim_field_enable_boot_bypass_dis (
-// .clk_i (clk_i),
-// .rst_ni (rst_ni),
-// .wvalid_i (reg2hw.conf.boot_bypass_disable.qe),
-// .wdata_i (reg2hw.conf.boot_bypass_disable.q),
-// .enable_o (boot_bypass_dis_pfe)
-// );
-
- assign boot_bypass_dis_pfe = (es_enb_e'(reg2hw.conf.boot_bypass_disable.q) == ES_FIELD_ON);
+ entropy_src_field_en #(
+ .FieldW(FieldEnableWidth),
+ .FieldEnVal(int'(ES_FIELD_ON))
+ ) u_entropy_src_field_en_boot_bypass_dis (
+ .clk_i (clk_i),
+ .rst_ni (rst_ni),
+ .wvalid_i (reg2hw.conf.boot_bypass_disable.qe),
+ .wdata_i (reg2hw.conf.boot_bypass_disable.q),
+ .enable_o (boot_bypass_dis_pfe)
+ );
assign es_route_to_sw = es_route_pfe;
assign es_bypass_to_sw = es_type_pfe;
diff --git a/hw/ip/entropy_src/rtl/entropy_src_field_en.sv b/hw/ip/entropy_src/rtl/entropy_src_field_en.sv
new file mode 100644
index 0000000..70d75b7
--- /dev/null
+++ b/hw/ip/entropy_src/rtl/entropy_src_field_en.sv
@@ -0,0 +1,54 @@
+// Copyright lowRISC contributors.
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+//
+// Supports writing a field that enables
+// a function within a module.
+// Requirements are that the function will
+// only be enabled when the field is written
+// the it is the inverse of the current field
+// setting. The can only toggle between the
+// the on value and the off value.
+
+
+module entropy_src_field_en #(
+ parameter int FieldW = 4,
+ parameter int FieldEnVal = 'ha
+) (
+ input logic clk_i ,
+ input logic rst_ni,
+ input logic wvalid_i,
+ input logic [FieldW-1:0] wdata_i,
+
+ output logic enable_o
+);
+
+ // signal
+ logic field_update;
+ logic [FieldW-1:0] field_value;
+ logic [FieldW-1:0] field_value_invert;
+
+ // flops
+ logic [FieldW-1:0] field_q, field_d;
+
+ assign field_value = FieldEnVal;
+ assign field_value_invert = ~field_value;
+
+ always_ff @(posedge clk_i or negedge rst_ni) begin
+ if (!rst_ni) begin
+ field_q <= field_value_invert;
+ end else begin
+ field_q <= field_d;
+ end
+ end
+
+ assign field_update = wvalid_i && (field_q == ~wdata_i) &&
+ ((wdata_i == field_value) ||
+ (wdata_i == field_value_invert));
+
+ assign field_d = field_update ? wdata_i : field_q;
+
+ assign enable_o = (field_q == field_value);
+
+
+endmodule
