Add LSU reading data

Author: outercloudstudio

src/main/scala/main/Lsu.scala

@@ -0,0 +1,60 @@
+import chisel3._
+import chisel3.util._
+import _root_.circt.stage.ChiselStage
+
+object LsuState extends ChiselEnum {
+  val Idle, Requesting = Value
+}
+
+class Lsu extends Module {
+  val io = IO(new Bundle {
+    val read = Input(Bool());
+    // val write = Input(Bool());
+
+    val address = Input(UInt(8.W));
+    // val value = 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 state = Output(LsuState());
+    val output = Output(UInt(8.W));
+  })
+
+  val state = RegInit(LsuState.Idle);
+  io.state := state;
+
+  val output = RegInit(0.U(8.W));
+  io.output := output;
+
+  val read_requested = RegInit(false.B);
+  io.read_requested := read_requested;
+
+  val read_address = RegInit(false.B);
+  io.read_address := read_address;
+
+  when(io.read) {
+    switch(io.state) {
+      is(LsuState.Idle) {
+        state := LsuState.Requesting;
+        read_requested := true.B;
+        read_address := io.address;
+      }
+
+      is(LsuState.Requesting) {
+        when(io.read_ready) {
+          state := LsuState.Idle;
+          read_requested := false.B;
+          output := io.read_data;
+        }
+      }
+    }
+  }
+}

src/main/scala/main/Main.scala

@@ -3,6 +3,6 @@ import chisel3.util._
 import _root_.circt.stage.ChiselStage
 
 object Main extends App {
-    println("Generating Alu")
-    emitVerilog(new Alu(), Array("--target-dir", "generated"))
+    emitVerilog(new Alu(), Array("--target-dir", "generated"));
+    emitVerilog(new Lsu(), Array("--target-dir", "generated"));
 }

src/test/scala/main/LsuTest.scala

@@ -0,0 +1,30 @@
+import chisel3._
+import chiseltest._
+import org.scalatest.flatspec.AnyFlatSpec
+
+class LsuTest extends AnyFlatSpec with ChiselScalatestTester {
+  "Lsu" should "work" in {
+    test(new Lsu) { dut =>
+      dut.io.read.poke(true.B);
+      dut.io.address.poke(1.U);
+
+      dut.clock.step(1);
+
+      dut.io.state.expect(LsuState.Requesting);
+      dut.io.read_requested.expect(true.B);
+      dut.io.read_address.expect(1.U);
+
+      dut.clock.step(1);
+      dut.clock.step(1);
+
+      dut.io.state.expect(LsuState.Requesting);
+      dut.io.read_ready.poke(true.B);
+      dut.io.read_data.poke(5.U);
+
+      dut.clock.step(1);
+
+      dut.io.state.expect(LsuState.Idle);
+      dut.io.output.expect(5.U);
+    }
+  }
+}