Add LSU Writing

Author: outercloudstudio

src/main/scala/main/Lsu.scala

@@ -9,20 +9,20 @@ object LsuState extends ChiselEnum {
 class Lsu extends Module {
   val io = IO(new Bundle {
     val read = Input(Bool());
-    // val write = Input(Bool());
+    val write = Input(Bool());
 
     val address = Input(UInt(8.W));
-    // val value = Input(UInt(8.W));
+    val data = Input(UInt(8.W));
 
     val read_requested = Output(Bool());
     val read_address = Output(UInt(8.W));
     val read_ready = Input(Bool());
     val read_data = Input(UInt(8.W));
 
-    // val write_ready = Input(Bool());
-    // val write_data = Output(UInt(8.W));
-    // val write_valid = Output(Bool());
-    // val write_address = Output(UInt(8.W));
+    val write_requested = Output(Bool());
+    val write_data = Output(UInt(8.W));
+    val write_address = Output(UInt(8.W));
+    val write_ready = Input(Bool());
 
     val state = Output(LsuState());
     val output = Output(UInt(8.W));
@@ -40,6 +40,15 @@ class Lsu extends Module {
   val read_address = RegInit(false.B);
   io.read_address := read_address;
 
+  val write_requested = RegInit(false.B);
+  io.write_requested := write_requested;
+
+  val write_address = RegInit(0.U(8.W));
+  io.write_address := write_address;
+
+  val write_data = RegInit(0.U(8.W));
+  io.write_data := write_data;
+
   when(io.read) {
     switch(io.state) {
       is(LsuState.Idle) {
@@ -57,4 +66,22 @@ class Lsu extends Module {
       }
     }
   }
+
+  when(io.write) {
+    switch(io.state) {
+      is(LsuState.Idle) {
+        state := LsuState.Requesting;
+        write_requested := true.B;
+        write_address := io.address;
+        write_data := io.data
+      }
+
+      is(LsuState.Requesting) {
+        when(io.write_ready) {
+          state := LsuState.Idle;
+          write_requested := false.B;
+        }
+      }
+    }
+  }
 }

src/test/scala/main/AluTest.scala

@@ -3,7 +3,7 @@ import chiseltest._
 import org.scalatest.flatspec.AnyFlatSpec
 
 class AluTest extends AnyFlatSpec with ChiselScalatestTester {
-  "Alu" should "work" in {
+  "Alu Add" should "work" in {
     test(new Alu) { dut =>
       dut.io.enable.poke(true.B);
       dut.io.operation.poke(AluOperation.Add);

src/test/scala/main/LsuTest.scala

@@ -3,7 +3,7 @@ import chiseltest._
 import org.scalatest.flatspec.AnyFlatSpec
 
 class LsuTest extends AnyFlatSpec with ChiselScalatestTester {
-  "Lsu" should "work" in {
+  "Lsu Read" should "work" in {
     test(new Lsu) { dut =>
       dut.io.read.poke(true.B);
       dut.io.address.poke(1.U);
@@ -27,4 +27,30 @@ class LsuTest extends AnyFlatSpec with ChiselScalatestTester {
       dut.io.output.expect(5.U);
     }
   }
+
+  "Lsu Write" should "work" in {
+    test(new Lsu) { dut =>
+      dut.io.write.poke(true.B);
+      dut.io.address.poke(1.U);
+      dut.io.data.poke(2.U);
+
+      dut.clock.step(1);
+
+      dut.io.state.expect(LsuState.Requesting);
+      dut.io.write_requested.expect(true.B);
+      dut.io.write_address.expect(1.U);
+      dut.io.write_data.expect(2.U);
+
+      dut.clock.step(1);
+      dut.clock.step(1);
+
+      dut.io.state.expect(LsuState.Requesting);
+
+      dut.io.write_ready.poke(true.B);
+
+      dut.clock.step(1);
+
+      dut.io.state.expect(LsuState.Idle);
+    }
+  }
 }