[entropy_src/dv] Fix usage of rng_max_delay plusarg

Previously, upon reading the plusarg, the specified value was immediately written to the configuration object of the RNG agent in the environment config. But as it turns out, the entropy_src_env_cfg holding the RNG agent which got the plusarg value is created before entropy_src_env. During the creation of the latter, a new RNG agent object is generated. This means the plusarg value got previously overwritten. This commit solves this issue by storing the plusarg value into a new configuration variable that can be used in entropy_src_env to configure the newly created RNG agent. Signed-off-by: Pirmin Vogel <[email protected]>
lowRISC · Mar 2, 2024 · 01b73a0 · 01b73a0
1 parent 2b9338d
commit 01b73a0
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Showing 3 changed files with 5 additions and 2 deletions.
diff --git a/hw/ip/entropy_src/dv/env/entropy_src_env.sv b/hw/ip/entropy_src/dv/env/entropy_src_env.sv
@@ -40,7 +40,7 @@ class entropy_src_env extends cip_base_env #(
  // on a test by test basis.
  cfg.m_rng_agent_cfg.zero_delays = 0;
  cfg.m_rng_agent_cfg.host_delay_min = 1;
- cfg.m_rng_agent_cfg.host_delay_max = 12;
+ cfg.m_rng_agent_cfg.host_delay_max = cfg.rng_max_delay;
  cfg.m_rng_agent_cfg.ignore_push_host_backpressure = cfg.rng_ignores_backpressure;
 
  m_csrng_agent = push_pull_agent#(.HostDataWidth(entropy_src_pkg::FIPS_CSRNG_BUS_WIDTH))::

diff --git a/hw/ip/entropy_src/dv/env/entropy_src_env_cfg.sv b/hw/ip/entropy_src/dv/env/entropy_src_env_cfg.sv
@@ -115,6 +115,9 @@ class entropy_src_env_cfg extends cip_base_env_cfg #(.RAL_T(entropy_src_reg_bloc
  // alert within alert_max_delay clock cycles.
  int alert_max_delay;
 
+ // host_delay_max value for the RNG agent. This can be overwritten using a plusarg.
+ int rng_max_delay = 12;
+
  // Whether to keep the default response on the XHT interface at all time.
  bit xht_only_default_rsp = 1;
 

diff --git a/hw/ip/entropy_src/dv/tests/entropy_src_base_test.sv b/hw/ip/entropy_src/dv/tests/entropy_src_base_test.sv
@@ -32,7 +32,7 @@ class entropy_src_base_test extends cip_base_test #(
  bit xht_only_default_rsp;
  if ($value$plusargs("rng_max_delay=%0d", rng_max_delay)) begin
  `uvm_info(`gfn, $sformatf("+rng_max_delay specified"), UVM_MEDIUM)
- cfg.m_rng_agent_cfg.host_delay_max = rng_max_delay;
+ cfg.rng_max_delay = rng_max_delay;
  end
  if ($value$plusargs("xht_only_default_rsp=%0b", xht_only_default_rsp)) begin
  `uvm_info(`gfn, $sformatf("+xht_only_default_rsp specified"), UVM_MEDIUM)