From bfb5a5bd6949d4a1b5d99fb24e07d885de7d472a Mon Sep 17 00:00:00 2001
From: Pirmin Vogel <vogelpi@lowrisc.org>
Date: Thu, 22 Aug 2024 13:27:11 +0200
Subject: [PATCH] [top_earlgrey] Reduce number of PRINCE half rounds for main
 SRAM

This commit reduces the number of PRINCE half rounds for the scrambling
of the main SRAM to 2 half rounds as used in the past. This is done
to reduce timing pressure.

Signed-off-by: Pirmin Vogel <vogelpi@lowrisc.org>
---
 hw/top_earlgrey/data/autogen/top_earlgrey.gen.hjson | 3 ++-
 hw/top_earlgrey/data/top_earlgrey.hjson             | 1 +
 hw/top_earlgrey/rtl/autogen/top_earlgrey.sv         | 2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/top_earlgrey/data/autogen/top_earlgrey.gen.hjson b/hw/top_earlgrey/data/autogen/top_earlgrey.gen.hjson
index fb1d7c03d25bb..3428d20d4bf31 100644
--- a/hw/top_earlgrey/data/autogen/top_earlgrey.gen.hjson
+++ b/hw/top_earlgrey/data/autogen/top_earlgrey.gen.hjson
@@ -7265,6 +7265,7 @@
       param_decl:
       {
         InstrExec: "1"
+        NumPrinceRoundsHalf: "2"
       }
       base_addrs:
       {
@@ -7353,7 +7354,7 @@
           name: NumPrinceRoundsHalf
           desc: Number of PRINCE half rounds for the SRAM scrambling feature
           type: int
-          default: "3"
+          default: "2"
           expose: "true"
           name_top: SramCtrlMainNumPrinceRoundsHalf
         }
diff --git a/hw/top_earlgrey/data/top_earlgrey.hjson b/hw/top_earlgrey/data/top_earlgrey.hjson
index 114208178c3ce..b2e8c38bb38a8 100644
--- a/hw/top_earlgrey/data/top_earlgrey.hjson
+++ b/hw/top_earlgrey/data/top_earlgrey.hjson
@@ -727,6 +727,7 @@
       reset_connections: {rst_ni: "lc", rst_otp_ni: "lc_io_div4"},
       param_decl: {
         InstrExec: "1",
+        NumPrinceRoundsHalf: "2",
       },
       base_addrs: {regs: "0x411C0000", ram: "0x10000000"},
       // Memory regions must be associated with a dedicated
diff --git a/hw/top_earlgrey/rtl/autogen/top_earlgrey.sv b/hw/top_earlgrey/rtl/autogen/top_earlgrey.sv
index c21b9b60e4db5..7bbfb7875374c 100644
--- a/hw/top_earlgrey/rtl/autogen/top_earlgrey.sv
+++ b/hw/top_earlgrey/rtl/autogen/top_earlgrey.sv
@@ -97,7 +97,7 @@ module top_earlgrey #(
   // parameters for edn1
   // parameters for sram_ctrl_main
   parameter bit SramCtrlMainInstrExec = 1,
-  parameter int SramCtrlMainNumPrinceRoundsHalf = 3,
+  parameter int SramCtrlMainNumPrinceRoundsHalf = 2,
   // parameters for rom_ctrl
   parameter RomCtrlBootRomInitFile = "",
   parameter bit SecRomCtrlDisableScrambling = 1'b0,