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authorJim Lawson2016-07-06 10:01:23 -0700
committerJim Lawson2016-07-18 15:17:56 -0700
commitc5f9ea3133ef363ff8944e17d94fea79767b6bed (patch)
treecc80a6df1eb58f0feaf9f138eb7fe261ccda4ea2 /chiselFrontend/src/main/scala/chisel3/core/BiConnect.scala
parent53813f61b7dfe246d214ab966739d01c65c8ecb0 (diff)
Rename "Chisel" to "chisel3" (only git mv).
Diffstat (limited to 'chiselFrontend/src/main/scala/chisel3/core/BiConnect.scala')
-rw-r--r--chiselFrontend/src/main/scala/chisel3/core/BiConnect.scala190
1 files changed, 190 insertions, 0 deletions
diff --git a/chiselFrontend/src/main/scala/chisel3/core/BiConnect.scala b/chiselFrontend/src/main/scala/chisel3/core/BiConnect.scala
new file mode 100644
index 00000000..42d85bfb
--- /dev/null
+++ b/chiselFrontend/src/main/scala/chisel3/core/BiConnect.scala
@@ -0,0 +1,190 @@
+package Chisel
+
+import internal.Builder.pushCommand
+import internal.firrtl.Connect
+import scala.language.experimental.macros
+import internal.sourceinfo.{SourceInfo, DeprecatedSourceInfo, UnlocatableSourceInfo, WireTransform, SourceInfoTransform}
+
+/**
+* BiConnect.connect executes a bidirectional connection element-wise.
+*
+* Note that the arguments are left and right (not source and sink) so the
+* intent is for the operation to be commutative.
+*
+* The connect operation will recurse down the left Data (with the right Data).
+* An exception will be thrown if a movement through the left cannot be matched
+* in the right (or if the right side has extra fields).
+*
+* See elemConnect for details on how the root connections are issued.
+*
+*/
+
+object BiConnect {
+ // These are all the possible exceptions that can be thrown.
+ case class BiConnectException(message: String) extends Exception(message)
+ // These are from element-level connection
+ def BothDriversException =
+ BiConnectException(": Both Left and Right are drivers")
+ def NeitherDriverException =
+ BiConnectException(": Neither Left nor Right is a driver")
+ def UnknownDriverException =
+ BiConnectException(": Locally unclear whether Left or Right (both internal)")
+ def UnknownRelationException =
+ BiConnectException(": Left or Right unavailable to current module.")
+ // These are when recursing down aggregate types
+ def MismatchedVecException =
+ BiConnectException(": Left and Right are different length Vecs.")
+ def MissingLeftFieldException(field: String) =
+ BiConnectException(s".$field: Left Bundle missing field ($field).")
+ def MissingRightFieldException(field: String) =
+ BiConnectException(s": Right Bundle missing field ($field).")
+ def MismatchedException(left: String, right: String) =
+ BiConnectException(s": Left ($left) and Right ($right) have different types.")
+
+ /** This function is what recursively tries to connect a left and right together
+ *
+ * There is some cleverness in the use of internal try-catch to catch exceptions
+ * during the recursive decent and then rethrow them with extra information added.
+ * This gives the user a 'path' to where in the connections things went wrong.
+ */
+ def connect(sourceInfo: SourceInfo, left: Data, right: Data, context_mod: Module): Unit =
+ (left, right) match {
+ // Handle element case (root case)
+ case (left_e: Element, right_e: Element) => {
+ elemConnect(sourceInfo, left_e, right_e, context_mod)
+ // TODO(twigg): Verify the element-level classes are connectable
+ }
+ // Handle Vec case
+ case (left_v: Vec[Data @unchecked], right_v: Vec[Data @unchecked]) => {
+ if(left_v.length != right_v.length) { throw MismatchedVecException }
+ for(idx <- 0 until left_v.length) {
+ try {
+ connect(sourceInfo, left_v(idx), right_v(idx), context_mod)
+ } catch {
+ case BiConnectException(message) => throw BiConnectException(s"($idx)$message")
+ }
+ }
+ }
+ // Handle Bundle case
+ case (left_b: Bundle, right_b: Bundle) => {
+ // Verify right has no extra fields that left doesn't have
+ for((field, right_sub) <- right_b.elements) {
+ if(!left_b.elements.isDefinedAt(field)) throw MissingLeftFieldException(field)
+ }
+ // For each field in left, descend with right
+ for((field, left_sub) <- left_b.elements) {
+ try {
+ right_b.elements.get(field) match {
+ case Some(right_sub) => connect(sourceInfo, left_sub, right_sub, context_mod)
+ case None => throw MissingRightFieldException(field)
+ }
+ } catch {
+ case BiConnectException(message) => throw BiConnectException(s".$field$message")
+ }
+ }
+ }
+ // Left and right are different subtypes of Data so fail
+ case (left, right) => throw MismatchedException(left.toString, right.toString)
+ }
+
+ // These functions (finally) issue the connection operation
+ // Issue with right as sink, left as source
+ private def issueConnectL2R(left: Element, right: Element)(implicit sourceInfo: SourceInfo): Unit = {
+ pushCommand(Connect(sourceInfo, right.lref, left.ref))
+ }
+ // Issue with left as sink, right as source
+ private def issueConnectR2L(left: Element, right: Element)(implicit sourceInfo: SourceInfo): Unit = {
+ pushCommand(Connect(sourceInfo, left.lref, right.ref))
+ }
+
+ // This function checks if element-level connection operation allowed.
+ // Then it either issues it or throws the appropriate exception.
+ def elemConnect(implicit sourceInfo: SourceInfo, left: Element, right: Element, context_mod: Module): Unit = {
+ import Direction.{Input, Output} // Using extensively so import these
+ // If left or right have no location, assume in context module
+ // This can occur if one of them is a literal, unbound will error previously
+ val left_mod: Module = left.binding.location.getOrElse(context_mod)
+ val right_mod: Module = right.binding.location.getOrElse(context_mod)
+
+ val left_direction: Option[Direction] = left.binding.direction
+ val right_direction: Option[Direction] = right.binding.direction
+ // None means internal
+
+ // CASE: Context is same module as left node and right node is in a child module
+ if( (left_mod == context_mod) &&
+ (right_mod._parent.map(_ == context_mod).getOrElse(false)) ) {
+ // Thus, right node better be a port node and thus have a direction hint
+ (left_direction, right_direction) match {
+ // CURRENT MOD CHILD MOD
+ case (Some(Input), Some(Input)) => issueConnectL2R(left, right)
+ case (None, Some(Input)) => issueConnectL2R(left, right)
+
+ case (Some(Output), Some(Output)) => issueConnectR2L(left, right)
+ case (None, Some(Output)) => issueConnectR2L(left, right)
+
+ case (Some(Input), Some(Output)) => throw BothDriversException
+ case (Some(Output), Some(Input)) => throw NeitherDriverException
+ case (_, None) => throw UnknownRelationException
+ }
+ }
+
+ // CASE: Context is same module as right node and left node is in child module
+ else if( (right_mod == context_mod) &&
+ (left_mod._parent.map(_ == context_mod).getOrElse(false)) ) {
+ // Thus, left node better be a port node and thus have a direction hint
+ (left_direction, right_direction) match {
+ // CHILD MOD CURRENT MOD
+ case (Some(Input), Some(Input)) => issueConnectR2L(left, right)
+ case (Some(Input), None) => issueConnectR2L(left, right)
+
+ case (Some(Output), Some(Output)) => issueConnectL2R(left, right)
+ case (Some(Output), None) => issueConnectL2R(left, right)
+
+ case (Some(Input), Some(Output)) => throw NeitherDriverException
+ case (Some(Output), Some(Input)) => throw BothDriversException
+ case (None, _) => throw UnknownRelationException
+ }
+ }
+
+ // CASE: Context is same module that both left node and right node are in
+ else if( (context_mod == left_mod) && (context_mod == right_mod) ) {
+ (left_direction, right_direction) match {
+ // CURRENT MOD CURRENT MOD
+ case (Some(Input), Some(Output)) => issueConnectL2R(left, right)
+ case (Some(Input), None) => issueConnectL2R(left, right)
+ case (None, Some(Output)) => issueConnectL2R(left, right)
+
+ case (Some(Output), Some(Input)) => issueConnectR2L(left, right)
+ case (Some(Output), None) => issueConnectR2L(left, right)
+ case (None, Some(Input)) => issueConnectR2L(left, right)
+
+ case (Some(Input), Some(Input)) => throw BothDriversException
+ case (Some(Output), Some(Output)) => throw NeitherDriverException
+ case (None, None) => throw UnknownDriverException
+ }
+ }
+
+ // CASE: Context is the parent module of both the module containing left node
+ // and the module containing right node
+ // Note: This includes case when left and right in same module but in parent
+ else if( (left_mod._parent.map(_ == context_mod).getOrElse(false)) &&
+ (right_mod._parent.map(_ == context_mod).getOrElse(false))
+ ) {
+ // Thus both nodes must be ports and have a direction hint
+ (left_direction, right_direction) match {
+ // CHILD MOD CHILD MOD
+ case (Some(Input), Some(Output)) => issueConnectR2L(left, right)
+ case (Some(Output), Some(Input)) => issueConnectL2R(left, right)
+
+ case (Some(Input), Some(Input)) => throw NeitherDriverException
+ case (Some(Output), Some(Output)) => throw BothDriversException
+ case (_, None) => throw UnknownRelationException
+ case (None, _) => throw UnknownRelationException
+ }
+ }
+
+ // Not quite sure where left and right are compared to current module
+ // so just error out
+ else throw UnknownRelationException
+ }
+}