From fb6e4b0faf270037914b1f8b19223fdf255f16a5 Mon Sep 17 00:00:00 2001
From: Deborah Soung <debs@sifive.com>
Date: Tue, 20 Feb 2024 08:34:36 -0800
Subject: [PATCH] Remove extra bit from `SRAMInterface` address width (#3830)

(cherry picked from commit 4f1f4a7744f2b9ea217e8c2972c312642755be1b)

# Conflicts:
#	src/test/scala/chiselTests/util/SRAMSpec.scala
---
 src/main/scala/chisel3/util/SRAM.scala        |  2 +-
 src/test/scala/chiselTests/Mem.scala          | 10 ++---
 .../scala/chiselTests/util/SRAMSpec.scala     | 45 +++++++++++++++++++
 3 files changed, 51 insertions(+), 6 deletions(-)
 create mode 100644 src/test/scala/chiselTests/util/SRAMSpec.scala

diff --git a/src/main/scala/chisel3/util/SRAM.scala b/src/main/scala/chisel3/util/SRAM.scala
index e8e4a291350..4da35e0fb5e 100644
--- a/src/main/scala/chisel3/util/SRAM.scala
+++ b/src/main/scala/chisel3/util/SRAM.scala
@@ -103,7 +103,7 @@ class SRAMInterface[T <: Data](
     s"SRAMInterface_${SRAM.portedness(numReadPorts, numWritePorts, numReadwritePorts)}${if (masked) "_masked"
     else ""}}_${tpe.typeName}"
 
-  val addrWidth = log2Up(memSize + 1)
+  val addrWidth = log2Up(memSize)
 
   val readPorts:  Vec[MemoryReadPort[T]] = Vec(numReadPorts, new MemoryReadPort(tpe, addrWidth))
   val writePorts: Vec[MemoryWritePort[T]] = Vec(numWritePorts, new MemoryWritePort(tpe, addrWidth, masked))
diff --git a/src/test/scala/chiselTests/Mem.scala b/src/test/scala/chiselTests/Mem.scala
index 92014cef621..760d036533e 100644
--- a/src/test/scala/chiselTests/Mem.scala
+++ b/src/test/scala/chiselTests/Mem.scala
@@ -529,10 +529,10 @@ class SRAMSpec extends ChiselFunSpec {
       val chirrtl = ChiselStage.emitCHIRRTL(new TestModule(1, 1), args = Array("--full-stacktrace"))
 
       chirrtl should include(
-        "writePorts : { flip address : UInt<6>, flip enable : UInt<1>, flip data : UInt<8>[3], flip mask : UInt<1>[3]}[1]"
+        "writePorts : { flip address : UInt<5>, flip enable : UInt<1>, flip data : UInt<8>[3], flip mask : UInt<1>[3]}[1]"
       )
       chirrtl should include(
-        "readwritePorts : { flip address : UInt<6>, flip enable : UInt<1>, flip isWrite : UInt<1>, readData : UInt<8>[3], flip writeData : UInt<8>[3], flip mask : UInt<1>[3]}[1]"
+        "readwritePorts : { flip address : UInt<5>, flip enable : UInt<1>, flip isWrite : UInt<1>, readData : UInt<8>[3], flip writeData : UInt<8>[3], flip mask : UInt<1>[3]}[1]"
       )
 
       for (i <- 0 until 3) {
@@ -576,13 +576,13 @@ class SRAMSpec extends ChiselFunSpec {
         val wrIndexSuffix = if (i == 0) "" else s"_$i"
 
         chirrtl should include(
-          s"read mport mem_out_readPorts_${i}_data_MPORT = mem_mem[_mem_out_readPorts_${i}_data_T], readClocks[${i}]"
+          s"read mport mem_out_readPorts_${i}_data_MPORT = mem_mem[_mem_out_readPorts_${i}_data_WIRE], readClocks[${i}]"
         )
         chirrtl should include(
-          s"write mport mem_MPORT${wrIndexSuffix} = mem_mem[_mem_T${wrIndexSuffix}], writeClocks[${i}]"
+          s"write mport mem_MPORT${wrIndexSuffix} = mem_mem[mem.writePorts[${i}].address], writeClocks[${i}]"
         )
         chirrtl should include(
-          s"rdwr mport mem_out_readwritePorts_${i}_readData_MPORT = mem_mem[_mem_out_readwritePorts_${i}_readData_T], readwriteClocks[${i}]"
+          s"rdwr mport mem_out_readwritePorts_${i}_readData_MPORT = mem_mem[_mem_out_readwritePorts_${i}_readData_WIRE], readwriteClocks[${i}]"
         )
       }
     }
diff --git a/src/test/scala/chiselTests/util/SRAMSpec.scala b/src/test/scala/chiselTests/util/SRAMSpec.scala
new file mode 100644
index 00000000000..79974e1d1ea
--- /dev/null
+++ b/src/test/scala/chiselTests/util/SRAMSpec.scala
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package chiselTests.util
+
+import chisel3._
+import chisel3.util.SRAM
+import chisel3.experimental.{annotate, ChiselAnnotation}
+import chiselTests.ChiselFlatSpec
+import _root_.circt.stage.ChiselStage.emitCHIRRTL
+import firrtl.annotations.{Annotation, ReferenceTarget, SingleTargetAnnotation}
+
+class SRAMSpec extends ChiselFlatSpec {
+  case class DummyAnno(target: ReferenceTarget) extends SingleTargetAnnotation[ReferenceTarget] {
+    override def duplicate(n: ReferenceTarget) = this.copy(target = n)
+  }
+  behavior.of("SRAMInterface")
+
+  it should "Provide target information about its instantiating SRAM" in {
+
+    class Top extends Module {
+      val sram = SRAM(
+        size = 32,
+        tpe = UInt(8.W),
+        numReadPorts = 0,
+        numWritePorts = 0,
+        numReadwritePorts = 1
+      )
+      require(sram.underlying.nonEmpty)
+      annotate(new ChiselAnnotation {
+        override def toFirrtl: Annotation = DummyAnno(sram.underlying.get.toTarget)
+      })
+    }
+    val (chirrtlCircuit, annos) = getFirrtlAndAnnos(new Top)
+    val chirrtl = chirrtlCircuit.serialize
+    chirrtl should include("module Top :")
+    chirrtl should include("smem sram_mem : UInt<8> [32]")
+    chirrtl should include(
+      "wire sram : { readPorts : { flip address : UInt<5>, flip enable : UInt<1>, data : UInt<8>}[0], writePorts : { flip address : UInt<5>, flip enable : UInt<1>, flip data : UInt<8>}[0], readwritePorts : { flip address : UInt<5>, flip enable : UInt<1>, flip isWrite : UInt<1>, readData : UInt<8>, flip writeData : UInt<8>}[1]}"
+    )
+
+    val dummyAnno = annos.collectFirst { case DummyAnno(t) => (t.toString) }
+    dummyAnno should be(Some("~Top|Top>sram_mem"))
+  }
+
+}