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// SPDX-License-Identifier: Apache-2.0
package chiselTests
import chisel3._
import chisel3.stage.ChiselStage
import chisel3.util._
class Risc extends Module {
val io = IO(new Bundle {
val isWr = Input(Bool())
val wrAddr = Input(UInt(8.W))
val wrData = Input(Bits(32.W))
val boot = Input(Bool())
val valid = Output(Bool())
val out = Output(Bits(32.W))
})
val memSize = 256
val file = Mem(memSize, Bits(32.W))
val code = Mem(memSize, Bits(32.W))
val pc = RegInit(0.U(8.W))
val add_op :: imm_op :: Nil = Enum(2)
val inst = code(pc)
val op = inst(31, 24)
val rci = inst(23, 16)
val rai = inst(15, 8)
val rbi = inst(7, 0)
val ra = Mux(rai === 0.U, 0.U, file(rai))
val rb = Mux(rbi === 0.U, 0.U, file(rbi))
val rc = Wire(Bits(32.W))
io.valid := false.B
io.out := 0.U
rc := 0.U
when(io.isWr) {
code(io.wrAddr) := io.wrData
}.elsewhen(io.boot) {
pc := 0.U
}.otherwise {
switch(op) {
is(add_op) { rc := ra +% rb }
is(imm_op) { rc := (rai << 8) | rbi }
}
io.out := rc
when(rci === 255.U) {
io.valid := true.B
}.otherwise {
file(rci) := rc
}
pc := pc +% 1.U
}
}
/*
class RiscTester(c: Risc) extends Tester(c) {
def wr(addr: BigInt, data: BigInt) = {
poke(c.io.isWr, 1)
poke(c.io.wrAddr, addr)
poke(c.io.wrData, data)
step(1)
}
def boot() = {
poke(c.io.isWr, 0)
poke(c.io.boot, 1)
step(1)
}
def tick(isBoot: Boolean) = {
if (isBoot)
poke(c.io.boot, 0)
step(1)
}
def I (op: UInt, rc: Int, ra: Int, rb: Int) = {
// val cr = Cat(op, rc.asUInt(8.W), ra.asUInt(8.W), rb.asUInt(8.W)).litValue()
val cr = op.litValue() << 24 | rc << 16 | ra << 8 | rb
println("I = " + cr)
cr
}
val app = Array(I(c.imm_op, 1, 0, 1), // r1 <- 1
I(c.add_op, 1, 1, 1), // r1 <- r1 + r1
I(c.add_op, 1, 1, 1), // r1 <- r1 + r1
I(c.add_op, 255, 1, 0)) // rh <- r1
wr(0, 0) // skip reset
for (addr <- 0 until app.length)
wr(addr, app(addr))
def dump(k: Int) {
println("K = " + k)
peek(c.ra)
peek(c.rb)
peek(c.rc)
peek(c.io.out)
peek(c.pc)
peek(c.inst)
peek(c.op)
peek(c.rci)
peek(c.rai)
peek(c.rbi)
peekAt(c.file, 1)
}
boot()
dump(0)
var k = 0
do {
tick(k == 0); k += 1
dump(k)
} while (!(peek(c.io.valid) == 1 || k > 10))
expect(k <= 10, "TIME LIMIT")
expect(c.io.out, 4)
}
*/
class RiscSpec extends ChiselPropSpec {
property("Risc should elaborate") {
ChiselStage.elaborate { new Risc }
}
ignore("RiscTester should return the correct result") {}
}
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