Add jal instruction

bench/tests/op/jal.s

@@ -0,0 +1,12 @@
+# expected: 00000004, 0000008, 0000000C
+    .text
+_start:
+    jal x31, step1
+step1:
+    jal x31, step2
+step2:
+    jal x31, step3
+step3:
+    nop
+
+

build.sc

@@ -14,28 +14,28 @@ import mill.bsp._
 // See: https://github.com/com-lihaoyi/mill/issues/3840
 
 object `TPchisel` extends SbtModule { m =>
-  override def millSourcePath = super.millSourcePath / os.up
-  override def scalaVersion = "2.13.16"
-  override def scalacOptions = Seq(
-    "-language:reflectiveCalls",
-    "-deprecation",
-    "-feature",
-    "-Xcheckinit",
-    "-Ymacro-annotations",
-    "-unchecked",
-	"-Xfatal-warnings", 
-	"-Ywarn-dead-code", 
-	"-Ywarn-unused" 
-  )
-  override def ivyDeps = Agg(
-    ivy"org.chipsalliance::chisel:7.2.0",
-  )
-  override def scalacPluginIvyDeps = Agg(
-    ivy"org.chipsalliance:::chisel-plugin:7.2.0",
-  )
-  object test extends SbtTests with TestModule.ScalaTest {
-    override def ivyDeps = m.ivyDeps() ++ Agg(
-      ivy"org.scalatest::scalatest::3.2.19"
+    override def millSourcePath = super.millSourcePath / os.up
+    override def scalaVersion = "2.13.16"
+    override def scalacOptions = Seq(
+        "-language:reflectiveCalls",
+        "-deprecation",
+        "-feature",
+        "-Xcheckinit",
+        "-Ymacro-annotations",
+        "-unchecked",
+        "-Xfatal-warnings",
+        "-Ywarn-dead-code",
+        "-Ywarn-unused"
     )
-  }
+    override def ivyDeps = Agg(
+        ivy"org.chipsalliance::chisel:7.2.0"
+    )
+    override def scalacPluginIvyDeps = Agg(
+        ivy"org.chipsalliance:::chisel-plugin:7.2.0"
+    )
+    object test extends SbtTests with TestModule.ScalaTest {
+        override def ivyDeps = m.ivyDeps() ++ Agg(
+            ivy"org.scalatest::scalatest::3.2.19"
+        )
+    }
 }

src/main/scala/projet/ControlUnit.scala

@@ -10,16 +10,21 @@ class CUInterface extends Bundle {
     val alu_opcode = Output(AluOpCode())
     val optype = Output(OpType())
 
+    // True if the decoded instruction is a jump
+    val is_jump = Output(Bool())
+
     // Muxers
     // The naming convention is as follows : mux_xxx_yyy.
     // If the signal is hot, xxx is selected otherwise yyy is selected
     val mux_alu_imm = Output(Bool())
     val mux_rega_pc = Output(Bool())
     val mux_regb_imm = Output(Bool())
+    val mux_incrpc4_imm = Output(Bool())
+    val mux_regpc_executepc = Output(Bool())
 }
 
 object OpType extends ChiselEnum {
-    val U, I, IR = Value
+    val U, I, IR, J = Value
 }
 
 object OpCode extends ChiselEnum {
@@ -46,6 +51,8 @@ object OpCode extends ChiselEnum {
     // add, and, or, xor, sll, srl, sra, slt, stlu
     val OpR = 0b0110011.U;
 
+    // Type J
+    val JAL = 0b1101111.U
 }
 
 
@@ -55,9 +62,12 @@ class ControlUnit() extends Module {
     io.reg_file_we := false.B
     io.alu_opcode := AluOpCode.Add
     io.optype := OpType.U
+    io.is_jump := false.B;
     io.mux_alu_imm := true.B;
     io.mux_rega_pc := true.B;
     io.mux_regb_imm := true.B;
+    io.mux_incrpc4_imm := true.B;
+    io.mux_regpc_executepc := true.B;
 
     // Decode instruction
     val opcode = io.instruction(6, 0);
@@ -76,21 +86,33 @@ class ControlUnit() extends Module {
             io.alu_opcode := AluOpCode.Add 
             io.reg_file_we := true.B // Write to regfile
             io.mux_rega_pc := false.B // Send PC to ALU A
-            io.mux_alu_imm := false.B; // Send immu to ALU B
+            io.mux_regb_imm := false.B; // Send immu to ALU B
             io.optype := OpType.U
         }
 
         // OpImm instructions
         is(OpCode.OpImm) {
-            io.reg_file_we := true.B
+            io.reg_file_we := true.B // Write to regfile
             opImm(funct3, funct7, io);
         }
         
         // OpR instructions
         is(OpCode.OpR) {
-            io.reg_file_we := true.B
+            io.reg_file_we := true.B // Write to regfile
             opR(funct3, funct7, io);
         }
+
+        // J instructions
+        is(OpCode.JAL) {
+            io.alu_opcode := AluOpCode.Add 
+            io.reg_file_we := true.B // Write to regfile
+            io.mux_rega_pc := false.B // Send PC to ALU A
+            io.mux_regb_imm := false.B; // Send imm to ALU B
+            io.is_jump := true.B
+            io.mux_incrpc4_imm := false.B; // Send the immediate in PC
+            io.mux_regpc_executepc := false.B; // Add the immediate to the previous PC
+            io.optype := OpType.J
+        }
     }
 
 

src/main/scala/projet/ImmediateDecoder.scala

@@ -20,6 +20,14 @@ class ImmediateDecoder extends Module {
     val imm_u = Cat(io.instruction(31, 12), 0.U(12.W));
     val imm_i = Cat(Fill(20, io.instruction(31)), io.instruction(31, 20));
     val imm_ir = io.instruction(24, 20);
+    val imm_j = Cat(
+        Fill(11, io.instruction(31)),
+        io.instruction(31),
+        io.instruction(19, 12),
+        io.instruction(20),
+        io.instruction(30, 21),
+        0.U
+    );
 
     switch(io.op_type) {
         is(OpType.U) {
@@ -31,5 +39,8 @@ class ImmediateDecoder extends Module {
         is(OpType.IR) {
             io.immediate := imm_ir
         }
+        is(OpType.J) {
+            io.immediate := imm_j
+        }
     }
 }

src/main/scala/projet/Rv32i.scala

@@ -12,32 +12,38 @@ class Rv32i(sim: Boolean = true) extends Module {
 
     val reg_pc = RegInit(0.U(32.W));
     val reg_file = Module(new RegFile(sim));
-    val instruction = io.ibus.rdata;
 
     reg_file.io.rd_data := 0.U;
     io.x31 := reg_file.io.x31
     if (sim) {
-        io.valid_x31.get := reg_file.io.valid_x31.get && Delay.Delay(
-            !reset.asBool,
-            1,
-            false.B
-        )
+        io.valid_x31.get := reg_file.io.valid_x31.get
     }
 
     val alu = Module(new Alu());
     val immediate_decoder = Module(new ImmediateDecoder());
     val control_unit = Module(new ControlUnit());
 
+    // PC delayed to execute stage for auipc op
+    val execute_pc = Delay.Delay(reg_pc, 1, 0.U);
+    // True if the instruction in the execute stage is a jump
+    val is_jump = Delay.Delay(control_unit.io.is_jump, 1, false.B);
+    val instruction = Mux(is_jump, 0b00000000000000000000000000010011.U, io.ibus.rdata);
+
     immediate_decoder.io.instruction := instruction
     immediate_decoder.io.op_type := control_unit.io.optype
     alu.io.opcode := control_unit.io.alu_opcode;
     reg_file.io.we := control_unit.io.reg_file_we
 
     // Increment PC each clock
-    reg_pc := reg_pc + 4.U;
-
-    // PC delayed to execute stage for auipc op
-    val execute_pc = Delay.Delay(reg_pc, 1, 0.U);
+    reg_pc := Mux(
+        control_unit.io.mux_regpc_executepc,
+        reg_pc,
+        execute_pc
+    ) + Mux(
+        control_unit.io.mux_incrpc4_imm,
+        4.U,
+        immediate_decoder.io.immediate
+    );
 
     // Fetch instruction
     io.ibus.en := true.B;

src/main/scala/projet/ZzTop.scala

@@ -24,7 +24,7 @@ class ZzTop(file: String = "", sim: Boolean = true) extends Module {
     // clock et reset sont les signaux implicites
     clkg.io.clk_in1 := clock
     clkg.io.reset := reset
-    val rst = (reset.asBool || !clkg.io.locked).asAsyncReset
+    val rst = reset.asBool || !clkg.io.locked
 
     // Ces deux IPs doivent tourner à 125 MHz
     val vmem = Module(new IDMem(sim, 17))
@@ -34,7 +34,7 @@ class ZzTop(file: String = "", sim: Boolean = true) extends Module {
     vgad.io.clk := clkg.io.clk_out2 // Clock pixel
 
     // Expose core for testing usage
-    val core = withClockAndReset(clkg.io.clk_out1, rst) {
+    withClockAndReset(clkg.io.clk_out1, rst) {
         val interconnect = Module(new BusInterconnect)
         val core = Module(new Rv32i(sim))
         val dmem = Module(new IDMem(sim, 16, file))
@@ -70,7 +70,5 @@ class ZzTop(file: String = "", sim: Boolean = true) extends Module {
         io.r := vgad.io.r
         io.g := vgad.io.g
         io.b := vgad.io.b
-
-        core
     }
 }