From cf0958c54ef1a0a596ccd4deeb37872be52dbd5b Mon Sep 17 00:00:00 2001
From: David Harris <david_harris@hmc.edu>
Date: Fri, 15 Jan 2021 00:25:56 -0500
Subject: [PATCH] Added GPIO

---
 wally-pipelined/src/dmem.sv           | 20 +++++++++++++-------
 wally-pipelined/src/gpio.sv           |  2 +-
 wally-pipelined/src/testbench.sv      |  7 ++++++-
 wally-pipelined/src/wallypipelined.sv |  7 +++++--
 4 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/wally-pipelined/src/dmem.sv b/wally-pipelined/src/dmem.sv
index dbe1401ed..f9014ffbc 100644
--- a/wally-pipelined/src/dmem.sv
+++ b/wally-pipelined/src/dmem.sv
@@ -34,27 +34,33 @@ module dmem #(parameter XLEN=32) (
   input  logic [XLEN-1:0] AdrM, WdM,
   output logic [XLEN-1:0] RdM,
   output logic            AccessFaultM,
-  output logic            TimerIntM, SwIntM);
+  output logic            TimerIntM, SwIntM,
+  input  logic [31:0] GPIOPinsIn,
+  output logic [31:0] GPIOPinsOut, GPIOPinsEn);
   
-  logic [XLEN-1:0] RdTimM, RdClintM;
-  logic            TimEnM, ClintEnM;
+  logic [XLEN-1:0] RdTimM, RdCLINTM, RdGPIOM;
+  logic            TimEnM, CLINTEnM, GPIOEnM;
 
   // Address decoding
+  // *** need to check top bits
   assign TimEnM = AdrM[31] & ~(|AdrM[30:19]); // 0x80000000 - 0x8007FFFF  *** check top bits too
-  assign ClintEnM = ~(|AdrM[XLEN-1:26]) & AdrM[25] & ~(|AdrM[24:16]); // 0x02000000-0x0200FFFF
+  assign CLINTEnM = ~(|AdrM[XLEN-1:26]) & AdrM[25] & ~(|AdrM[24:16]); // 0x02000000-0x0200FFFF
+  assign GPIOEnM = (AdrM[31:8] == 24'h10012); // 0x10012000-0x100120FF
 
   // tightly integrated memory
   dtim #(XLEN) dtim(clk, MemRWM & {2{TimEnM}}, ByteMaskM, AdrM[18:0], WdM, RdTimM);
 
   // memory-mapped I/O peripherals
-  clint #(XLEN) clint(clk, reset, MemRWM & {2{ClintEnM}}, ByteMaskM, AdrM[15:0], WdM, RdClintM,
+  clint #(XLEN) clint(clk, reset, MemRWM & {2{CLINTEnM}}, ByteMaskM, AdrM[15:0], WdM, RdCLINTM,
     TimerIntM, SwIntM);
+  gpio #(XLEN) gpio(clk, reset, MemRWM & {2{GPIOEnM}}, ByteMaskM, AdrM[7:0], WdM, RdGPIOM,
+    GPIOPinsIn, GPIOPinsOut, GPIOPinsEn);
 
   // *** add cache and interface to external memory & other peripherals
   
   // merge reads
-  assign RdM = RdTimM | RdClintM;
-  assign AccessFaultM = ~(|TimEnM | ClintEnM);
+  assign RdM = RdTimM | RdCLINTM | RdGPIOM;
+  assign AccessFaultM = ~(|TimEnM | CLINTEnM | GPIOEnM);
 
 endmodule
 
diff --git a/wally-pipelined/src/gpio.sv b/wally-pipelined/src/gpio.sv
index dad7d80d9..7415de2cb 100644
--- a/wally-pipelined/src/gpio.sv
+++ b/wally-pipelined/src/gpio.sv
@@ -37,7 +37,7 @@ module gpio #(parameter XLEN=32) (
   input  logic [31:0]     GPIOPinsIn,
   output logic [31:0]     GPIOPinsOut, GPIOPinsEn);
 
-  logic [31:0] INPUT_VAL INPUT_EN, OUTPUT_EN, OUTPUT_VAL;
+  logic [31:0] INPUT_VAL, INPUT_EN, OUTPUT_EN, OUTPUT_VAL;
  
   logic [XLEN-1:0] read, write;
   logic [15:0] entry;
diff --git a/wally-pipelined/src/testbench.sv b/wally-pipelined/src/testbench.sv
index 91c77217a..bb22b5ff7 100644
--- a/wally-pipelined/src/testbench.sv
+++ b/wally-pipelined/src/testbench.sv
@@ -231,8 +231,13 @@ string tests32i[] = {
     end
   string signame, memfilename;
 
+  logic [31:0] GPIOPinsIn, GPIOPinsOut, GPIOPinsEn;
+
   // instantiate device to be tested
-  wallypipelined #(XLEN, MISA, ZCSR, ZCOUNTERS) dut(clk, reset, WriteData, DataAdr, MemRW);
+  wallypipelined #(XLEN, MISA, ZCSR, ZCOUNTERS) dut(
+    clk, reset, WriteData, DataAdr, MemRW, 
+    GPIOPinsIn, GPIOPinsOut, GPIOPinsEn
+  ); 
 
   // Track names of instructions
   instrTrackerTB #(XLEN) it(clk, reset, dut.hart.dp.FlushE,
diff --git a/wally-pipelined/src/wallypipelined.sv b/wally-pipelined/src/wallypipelined.sv
index e57fcc36e..b1944349d 100644
--- a/wally-pipelined/src/wallypipelined.sv
+++ b/wally-pipelined/src/wallypipelined.sv
@@ -55,7 +55,10 @@
 module wallypipelined #(parameter XLEN=32, MISA=0, ZCSR = 1, ZCOUNTERS = 1) (
   input  logic            clk, reset, 
   output logic [XLEN-1:0] WriteDataM, DataAdrM, 
-  output logic [1:0]      MemRWM);
+  output logic [1:0]      MemRWM,
+  input  logic [31:0]     GPIOPinsIn,
+  output logic [31:0]     GPIOPinsOut, GPIOPinsEn
+);
 
   logic [XLEN-1:0] PCF, ReadDataM;
   logic [31:0] InstrF;
@@ -71,5 +74,5 @@ module wallypipelined #(parameter XLEN=32, MISA=0, ZCSR = 1, ZCOUNTERS = 1) (
 
   imem #(XLEN) imem(PCF, InstrF, InstrAccessFaultF);
   dmem #(XLEN) dmem(clk, reset, MemRWM, ByteMaskM, DataAdrM, WriteDataM, ReadDataM,
-    DataAccessFaultM, TimerIntM, SwIntM);
+    DataAccessFaultM, TimerIntM, SwIntM, GPIOPinsIn, GPIOPinsOut, GPIOPinsEn);
 endmodule
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