From 2cd2fe0828c85c33a6b6ade80a37f331f52a599a Mon Sep 17 00:00:00 2001
From: kipmacsaigoren <kmacsaigoren@hmc.edu>
Date: Wed, 15 Sep 2021 12:15:53 -0500
Subject: [PATCH 1/4] Added git things to make it all a little nicer and
 synthesis work.

---
 .gitmodules | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.gitmodules b/.gitmodules
index e69de29bb..65e1e71c9 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "sky130/sky130_osu_sc_t12"]
+	path = sky130/sky130_osu_sc_t12
+	url = https://foss-eda-tools.googlesource.com/skywater-pdk/libs/sky130_osu_sc_t12/

From 97c474327c7d9c45b8ae682e3cf7c19ce9cf4f0c Mon Sep 17 00:00:00 2001
From: kipmacsaigoren <kmacsaigoren@hmc.edu>
Date: Wed, 15 Sep 2021 12:24:24 -0500
Subject: [PATCH 2/4] changed priority circuits for synthesis and light cleanup

---
 wally-pipelined/src/mmu/pmpadrdec.sv           |  2 +-
 wally-pipelined/src/mmu/priorityonehot.sv      | 17 ++++++++++-------
 wally-pipelined/src/mmu/prioritythermometer.sv |  8 ++++++--
 3 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/wally-pipelined/src/mmu/pmpadrdec.sv b/wally-pipelined/src/mmu/pmpadrdec.sv
index 618167827..9fe28b261 100644
--- a/wally-pipelined/src/mmu/pmpadrdec.sv
+++ b/wally-pipelined/src/mmu/pmpadrdec.sv
@@ -82,7 +82,7 @@ module pmpadrdec (
   assign NAMask[1:0] = {2'b11};
 
   prioritythemometer #(`PA_BITS-2) namaskgen(
-    .a({PMPAdr[`PA_BITS-4:0], (AdrMode == NAPOT)}),
+    .a({~PMPAdr[`PA_BITS-4:0], (AdrMode == NAPOT)}), // *** confusing bit bussing to match the logic for the inside of the thermometer.
     .y(NAMask[`PA_BITS-1:2]));
 
   assign NAMatch = &((PhysicalAddress ~^ CurrentAdrFull) | NAMask);
diff --git a/wally-pipelined/src/mmu/priorityonehot.sv b/wally-pipelined/src/mmu/priorityonehot.sv
index 7a17f8d28..f02f8ccc5 100644
--- a/wally-pipelined/src/mmu/priorityonehot.sv
+++ b/wally-pipelined/src/mmu/priorityonehot.sv
@@ -40,13 +40,16 @@ module priorityonehot #(parameter ENTRIES = 8) (
   logic [ENTRIES-1:0] nolower;
 
   // generate thermometer code mask
-  genvar i;
-  generate
-    assign nolower[0] = 1'b1;
-    for (i=1; i<ENTRIES; i++) begin:therm
-      assign nolower[i] = nolower[i-1] & ~a[i-1];
-    end
-  endgenerate
+  prioritythemometer #(ENTRIES) maskgen(.a({a[ENTRIES-2:0], 1'b1}), .y(nolower));
+  // genvar i;
+  // generate
+  //   assign nolower[0] = 1'b1;
+  //   for (i=1; i<ENTRIES; i++) begin:therm
+  //     assign nolower[i] = nolower[i-1] & ~a[i-1];
+  //   end
+  // endgenerate
+  // *** replace mask generation logic ^^^ with priority thermometer
+
 
   assign y = a & nolower;
 
diff --git a/wally-pipelined/src/mmu/prioritythermometer.sv b/wally-pipelined/src/mmu/prioritythermometer.sv
index a6374579c..a3eab7e43 100644
--- a/wally-pipelined/src/mmu/prioritythermometer.sv
+++ b/wally-pipelined/src/mmu/prioritythermometer.sv
@@ -37,16 +37,20 @@ module prioritythemometer #(parameter N = 8) (
   output logic  [N-1:0] y
 );
 
+// Carefully crafted so design compiler would synthesize into a fast tree structure
+//  Rather than linear.
 
   // generate thermometer code mask
   genvar i;
   generate
     assign y[0] = a[0];
-    for (i=1; i<N; i++) begin
-      assign y[i] = y[i-1] & a[i];
+    for (i=1; i<N; i++) begin:therm
+      assign y[i] = y[i-1] & ~a[i]; // *** made to be the same as onehot (without the inverter) to see if the probelme is something weird with synthesis
+      // assign y[i] = y[i-1] & a[i];
     end
   endgenerate
 
+
 endmodule
 
 

From cc4ad218cb9a77bee22876d173166255222fcfee Mon Sep 17 00:00:00 2001
From: kipmacsaigoren <kmacsaigoren@hmc.edu>
Date: Fri, 17 Sep 2021 12:00:38 -0500
Subject: [PATCH 3/4] added new fun ways of putting inputs into the priority
 thermometer

---
 wally-pipelined/src/mmu/pmpadrdec.sv | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/wally-pipelined/src/mmu/pmpadrdec.sv b/wally-pipelined/src/mmu/pmpadrdec.sv
index 9fe28b261..46ee6bdcb 100644
--- a/wally-pipelined/src/mmu/pmpadrdec.sv
+++ b/wally-pipelined/src/mmu/pmpadrdec.sv
@@ -81,8 +81,16 @@ module pmpadrdec (
 
   assign NAMask[1:0] = {2'b11};
 
+// *** BAD DELETE LATER ADDED for hopefully fixing synth
+  logic [`PA_BITS-3:0] maskInput;
+
+  assign maskInput = `PA_BITS'd39; // *** added to really just try anything with the inputs of the thermometer.
+
+  // *** maskinput used to be {~PMPAdr[`PA_BITS-4:0], (AdrMode == NAPOT)}
+// ****
+
   prioritythemometer #(`PA_BITS-2) namaskgen(
-    .a({~PMPAdr[`PA_BITS-4:0], (AdrMode == NAPOT)}), // *** confusing bit bussing to match the logic for the inside of the thermometer.
+    .a(maskInput), // *** confusing bit bussing to match the logic for the inside of the thermometer.
     .y(NAMask[`PA_BITS-1:2]));
 
   assign NAMatch = &((PhysicalAddress ~^ CurrentAdrFull) | NAMask);

From 4de4774a71f01f9cda381da13324b8a84eb12456 Mon Sep 17 00:00:00 2001
From: Kip Macsai-Goren <kipmacsaigoren@github.com>
Date: Fri, 17 Sep 2021 13:07:21 -0400
Subject: [PATCH 4/4] more input changes on prioirty thermometer. passes lint

---
 wally-pipelined/src/mmu/pmpadrdec.sv | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/wally-pipelined/src/mmu/pmpadrdec.sv b/wally-pipelined/src/mmu/pmpadrdec.sv
index 46ee6bdcb..584b18fba 100644
--- a/wally-pipelined/src/mmu/pmpadrdec.sv
+++ b/wally-pipelined/src/mmu/pmpadrdec.sv
@@ -84,7 +84,7 @@ module pmpadrdec (
 // *** BAD DELETE LATER ADDED for hopefully fixing synth
   logic [`PA_BITS-3:0] maskInput;
 
-  assign maskInput = `PA_BITS'd39; // *** added to really just try anything with the inputs of the thermometer.
+  assign maskInput = 'd39; // *** added to really just try anything with the inputs of the thermometer.
 
   // *** maskinput used to be {~PMPAdr[`PA_BITS-4:0], (AdrMode == NAPOT)}
 // ****