[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>
vogelpi · Aug 22, 2024 · bfb5a5b · bfb5a5b
1 parent 7beee37
commit bfb5a5b
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Showing 3 changed files with 4 additions and 2 deletions.
diff --git 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
@@ -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
@@ -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,