From b0263012e8b37b7b92dba9200e52a4d967209612 Mon Sep 17 00:00:00 2001
From: David Harris <david_harris@hmc.edu>
Date: Sat, 15 Jan 2022 00:11:30 +0000
Subject: [PATCH] LSU cleanup

---
 pipelined/src/ebu/ahblite.sv |  2 +-
 pipelined/src/lsu/lsu.sv     | 13 +++----------
 2 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/pipelined/src/ebu/ahblite.sv b/pipelined/src/ebu/ahblite.sv
index 4a6057c94..bcc522a42 100644
--- a/pipelined/src/ebu/ahblite.sv
+++ b/pipelined/src/ebu/ahblite.sv
@@ -61,7 +61,7 @@ module ahblite (
   (* mark_debug = "true" *) input logic [`AHBW-1:0] HRDATA,
   (* mark_debug = "true" *) input logic HREADY, HRESP,
   (* mark_debug = "true" *) output logic HCLK, HRESETn,
-  (* mark_debug = "true" *) output logic [31:0] HADDR, 
+  (* mark_debug = "true" *) output logic [31:0] HADDR, // *** one day switch to a different bus that supports the full physical address
   (* mark_debug = "true" *) output logic [`AHBW-1:0] HWDATA,
   (* mark_debug = "true" *) output logic HWRITE, 
   (* mark_debug = "true" *) output logic [2:0] HSIZE,
diff --git a/pipelined/src/lsu/lsu.sv b/pipelined/src/lsu/lsu.sv
index 69254520b..1a4056f12 100644
--- a/pipelined/src/lsu/lsu.sv
+++ b/pipelined/src/lsu/lsu.sv
@@ -122,17 +122,9 @@ module lsu
   logic 					   BusCommittedM, DCacheCommittedM;
   
 
-  // Execute Stage Logic
-
-
-  // Execute-Memory Stage Registers (and Cache fires on this edge)
-
   flopenrc #(`XLEN) AddressMReg(clk, reset, FlushM, ~StallM, IEUAdrE, IEUAdrM);
-
-  // Memory Stage Logic
-
-  assign IEUAdrExtM = {2'b00, IEUAdrM};
-
+  assign IEUAdrExtM = {2'b00, IEUAdrM}; // *** probably needs to connect to external bus too, make external bus PADDRBITS
+ 
   ////////////////////////////////////////////////////////////////////////////////////////////////
   // HPTW and Interlock FSM (only needed if VM supported)
   // MMU include PMP and is needed if any privileged supported
@@ -169,6 +161,7 @@ module lsu
     mux2 #(12) adremux(IEUAdrE[11:0], HPTWAdr[11:0], SelHPTW, PreLSUAdrE);
     // When replaying CPU memory request after PTW select the IEUAdrM for correct address.
     assign LSUAdrE = SelReplayCPURequest ? IEUAdrM[11:0] : PreLSUAdrE;
+   
     mux2 #(`PA_BITS) lsupadrmux(IEUAdrExtM[`PA_BITS-1:0], HPTWAdr, SelHPTW, PreLSUPAdrM);
 
     // always block interrupts when using the hardware page table walker.