Packages

p

chisel3

package chisel3

This package contains the main chisel3 API.

Source
package.scala
Linear Supertypes
Content Hierarchy
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. chisel3
  2. AnyRef
  3. Any
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. Protected

Package Members

  1. package aop
  2. package choice

    This package contains Chisel language definitions for describing configuration options and their accepted values.

  3. package connectable
  4. package experimental

    Package for experimental features, which may have their API changed, be removed, etc.

    Package for experimental features, which may have their API changed, be removed, etc.

    Because its contents won't necessarily have the same level of stability and support as non-experimental, you must explicitly import this package to use its contents.

  5. package interface
  6. package ltl
  7. package naming
  8. package probe
  9. package properties

    The properties package includes functionality related to non-hardware data.

    The properties package includes functionality related to non-hardware data.

    This entire package is currently very experimental, so expect some rough edges and rapid API evolution.

  10. package reflect
  11. package simulator
  12. package stage
  13. package std
  14. package testers

    The testers package provides the basic interface for chisel testers.

  15. package util

    The util package provides extensions to core chisel for common hardware components and utility functions

Type Members

  1. sealed abstract class ActualDirection extends AnyRef

    Resolved directions for both leaf and container nodes, only visible after a node is bound (since higher-level specifications like Input and Output can override directions).

  2. sealed abstract class Aggregate extends Data

    An abstract class for data types that solely consist of (are an aggregate of) other Data objects.

  3. class AliasedAggregateFieldException extends ChiselException
  4. sealed class AsyncReset extends Element with Reset

    Data type representing asynchronous reset signals

    Data type representing asynchronous reset signals

    These signals are similar to Clocks in that they must be glitch-free for proper circuit operation. Regs defined with the implicit reset being an AsyncReset will be asychronously reset registers.

  5. class AutoClonetypeException extends ChiselException
  6. case class BiConnectException(message: String) extends ChiselException with Product with Serializable
  7. case class Binary(bits: Bits) extends FirrtlFormat with Product with Serializable

    Format bits as Binary

  8. class BindingException extends ChiselException
  9. sealed abstract class Bits extends Element with ToBoolable

    A data type for values represented by a single bitvector.

    A data type for values represented by a single bitvector. This provides basic bitwise operations.

  10. abstract class BlackBox extends BaseBlackBox

    Defines a black box, which is a module that can be referenced from within Chisel, but is not defined in the emitted Verilog.

    Defines a black box, which is a module that can be referenced from within Chisel, but is not defined in the emitted Verilog. Useful for connecting to RTL modules defined outside Chisel.

    Example:
    1. Some design require a differential input clock to clock the all design. With the xilinx FPGA for example, a Verilog template named IBUFDS must be integrated to use differential input:

      IBUFDS #(.DIFF_TERM("TRUE"),
               .IOSTANDARD("DEFAULT")) ibufds (
       .IB(ibufds_IB),
       .I(ibufds_I),
       .O(ibufds_O)
      );

      To instantiate it, a BlackBox can be used like following:

      import chisel3._
      import chisel3.experimental._
      
      // Example with Xilinx differential buffer IBUFDS
      class IBUFDS extends BlackBox(Map("DIFF_TERM" -> "TRUE", // Verilog parameters
                                        "IOSTANDARD" -> "DEFAULT"
                           )) {
        val io = IO(new Bundle {
          val O = Output(Clock()) // IO names will be the same
          val I = Input(Clock())  // (without 'io_' in prefix)
          val IB = Input(Clock()) //
        })
      }
    Note

    The parameters API is experimental and may change

  11. sealed class Bool extends UInt with Reset

    A data type for booleans, defined as a single bit indicating true or false.

  12. trait BoolFactory extends AnyRef
  13. abstract class Bundle extends Record

    Base class for data types defined as a bundle of other data types.

    Base class for data types defined as a bundle of other data types.

    Usage: extend this class (either as an anonymous or named class) and define members variables of Data subtypes to be elements in the Bundle.

    Example of an anonymous IO bundle

    class MyModule extends Module {
      val io = IO(new Bundle {
        val in = Input(UInt(64.W))
        val out = Output(SInt(128.W))
      })
    }

    Or as a named class

    class Packet extends Bundle {
      val header = UInt(16.W)
      val addr   = UInt(16.W)
      val data   = UInt(32.W)
    }
    class MyModule extends Module {
      val inPacket = IO(Input(new Packet))
      val outPacket = IO(Output(new Packet))
      val reg = Reg(new Packet)
      reg := inPacket
      outPacket := reg
    }

    The fields of a Bundle are stored in an ordered Map called "elements" in reverse order of definition

    class MyBundle extends Bundle {
      val foo = UInt(8.W)
      val bar = UInt(8.W)
    }
    val wire = Wire(new MyBundle)
    wire.elements // VectorMap("bar" -> wire.bar, "foo" -> wire.foo)
  14. case class Character(bits: Bits) extends FirrtlFormat with Product with Serializable

    Format bits as Character

  15. abstract class ChiselEnum extends AnyRef
  16. class ChiselException extends Exception
  17. sealed class Clock extends Element
  18. type Connectable[T <: Data] = chisel3.connectable.Connectable[T]
  19. abstract class Data extends HasId with NamedComponent with SourceInfoDoc

    This forms the root of the type system for wire data types.

    This forms the root of the type system for wire data types. The data value must be representable as some number (need not be known at Chisel compile time) of bits, and must have methods to pack / unpack structured data to / from bits.

  20. case class Decimal(bits: Bits) extends FirrtlFormat with Product with Serializable

    Format bits as Decimal

  21. class Disable extends AnyRef

    API for handling disabling of simulation constructs

    API for handling disabling of simulation constructs

    Disables may be non-synthesizable so they can only be used for disabling simulation constructs

    The default disable is the "hasBeenReset" of the currently in scope reset. It can be set by the user via the withDisable API

    Users can access the current Disable with Module.disable

  22. abstract class Element extends Data

    Element is a leaf data type: it cannot contain other Data objects.

    Element is a leaf data type: it cannot contain other Data objects. Example uses are for representing primitive data types, like integers and bits.

  23. abstract class EnumType extends Element
  24. case class ExpectedChiselTypeException(message: String) extends BindingException with Product with Serializable

    A function expected a Chisel type but got a hardware object

  25. case class ExpectedHardwareException(message: String) extends BindingException with Product with Serializable

    A function expected a hardware object but got a Chisel type

  26. sealed abstract class FirrtlFormat extends Printable

    Superclass for Firrtl format specifiers for Bits

  27. sealed trait FixedIOBaseModule[A <: Data] extends BaseModule

    A module or external module whose IO is generated from a specific generator.

    A module or external module whose IO is generated from a specific generator. This module may have no additional IO created other than what is specified by its ioGenerator abstract member.

  28. class FixedIOExtModule[A <: Data] extends ExtModule with FixedIOBaseModule[A]

    A Chisel blackbox whose IO is determined by an IO generator.

    A Chisel blackbox whose IO is determined by an IO generator. This module cannot have additional IO created by modules that extend it.

  29. class FixedIORawModule[A <: Data] extends RawModule with FixedIOBaseModule[A]

    A Chisel module whose IO is determined by an IO generator.

    A Chisel module whose IO is determined by an IO generator. This module cannot have additional IO created by modules that extend it.

  30. case class FullName(data: Data) extends Printable with Product with Serializable

    Put full name within parent namespace (eg.

    Put full name within parent namespace (eg. bundleName.field)

  31. sealed trait HasTarget extends AnyRef

    Contains universal methods for target accesses.

  32. case class Hexadecimal(bits: Bits) extends FirrtlFormat with Product with Serializable

    Format bits as Hexidecimal

  33. trait IgnoreSeqInBundle extends AnyRef

    Mix-in for Bundles that have arbitrary Seqs of Chisel types that aren't involved in hardware construction.

    Mix-in for Bundles that have arbitrary Seqs of Chisel types that aren't involved in hardware construction.

    Used to avoid raising an error/exception when a Seq is a public member of the bundle. This is useful if we those public Seq fields in the Bundle are unrelated to hardware construction.

  34. trait ImplicitClock extends AnyRef

    Provides an implicit Clock for use _within_ the RawModule

    Provides an implicit Clock for use _within_ the RawModule

    Be careful to define the Clock value before trying to use it. Due to Scala initialization order, the actual val defining the Clock must occur before any uses of the implicit Clock.

    Example:
    1. class MyModule extends RawModule with ImplicitClock {
        // Define a Clock value, it need not be called "implicitClock"
        val clk = IO(Input(Clock()))
        // Implement the virtual method to tell Chisel about this Clock value
        // Note that though this is a def, the actual Clock is assigned to a val (clk above)
        override protected def implicitClock = clk
        // Now we have a Clock to use in this RawModule
        val reg = Reg(UInt(8.W))
      }
  35. trait ImplicitReset extends AnyRef

    Provides an implicit Reset for use _within_ the RawModule

    Provides an implicit Reset for use _within_ the RawModule

    Be careful to define the Reset value before trying to use it. Due to Scala initialization order, the actual val defining the Reset object must occur before any uses of the implicit Reset.

    Example:
    1. class MyModule extends RawModule with ImplicitReset {
        // Define a Reset value, it need not be called "implicitReset"
        val rst = IO(Input(AsyncReset()))
        // Implement the virtual method to tell Chisel about this Reset value
        // Note that though this is a def, the actual Reset is assigned to a val (rst above)
        override protected def implicitReset = clk
        // Now we have a Reset to use in this RawModule
        // Registers also require a clock
        val clock = IO(Input(Clock()))
        val reg = withClock(clock)(RegInit(0.U)) // Combine with ImplicitClock to get rid of this withClock
      }
  36. trait InstanceId extends AnyRef

    Public API to access Node/Signal names.

    Public API to access Node/Signal names. currently, the node's name, the full path name, and references to its parent Module and component. These are only valid once the design has been elaborated, and should not be used during its construction.

  37. class InternalErrorException extends ChiselException
  38. sealed case class KnownWidth(value: Int) extends Width with Product with Serializable
  39. sealed class Mem[T <: Data] extends MemBase[T]

    A combinational/asynchronous-read, sequential/synchronous-write memory.

    A combinational/asynchronous-read, sequential/synchronous-write memory.

    Writes take effect on the rising clock edge after the request. Reads are combinational (requests will return data on the same cycle). Read-after-write hazards are not an issue.

    Note

    when multiple conflicting writes are performed on a Mem element, the result is undefined (unlike Vec, where the last assignment wins)

  40. sealed abstract class MemBase[T <: Data] extends HasId with NamedComponent with SourceInfoDoc
  41. case class MixedDirectionAggregateException(message: String) extends BindingException with Product with Serializable

    An aggregate had a mix of specified and unspecified directionality children

  42. abstract class Module extends RawModule with ImplicitClock with ImplicitReset

    Abstract base class for Modules, which behave much like Verilog modules.

    Abstract base class for Modules, which behave much like Verilog modules. These may contain both logic and state which are written in the Module body (constructor). This abstract base class includes an implicit clock and reset.

    Note

    Module instantiations must be wrapped in a Module() call.

  43. abstract class ModuleAspect extends RawModule with PseudoModule

    Used by Chisel Aspects to inject Chisel code into modules, after they have been elaborated.

    Used by Chisel Aspects to inject Chisel code into modules, after they have been elaborated. This is an internal API - don't use!

    It adds itself as an aspect to the module, which allows proper checking of connection and binding legality.

  44. case class MonoConnectException(message: String) extends ChiselException with Product with Serializable
  45. case class Name(data: Data) extends Printable with Product with Serializable

    Put innermost name (eg.

    Put innermost name (eg. field of bundle)

  46. trait Num[T <: Data] extends AnyRef

    Abstract trait defining operations available on numeric-like hardware data types.

    Abstract trait defining operations available on numeric-like hardware data types.

    T

    the underlying type of the number

  47. trait NumObject extends AnyRef

    NumbObject has a lot of convenience methods for converting between BigInts and Double and BigDecimal

  48. case class PString(str: String) extends Printable with Product with Serializable

    Wrapper for printing Scala Strings

  49. sealed abstract class Printable extends AnyRef

    Superclass of things that can be printed in the resulting circuit

    Superclass of things that can be printed in the resulting circuit

    Usually created using the custom string interpolator p"...". Printable string interpolation is similar to String interpolation in Scala For example:

    printf(p"The value of wire = $wire\n")

    This is equivalent to writing:

    printf("The value of wire = %d\n", wire)

    All Chisel data types have a method .toPrintable that gives a default pretty print that can be accessed via p"...". This works even for aggregate types, for example:

    val myVec = VecInit(5.U, 10.U, 13.U)
    printf(p"myVec = $myVec\n")
    // myVec = Vec(5, 10, 13)
    
    val myBundle = Wire(new Bundle {
      val foo = UInt()
      val bar = UInt()
    })
    myBundle.foo := 3.U
    myBundle.bar := 11.U
    printf(p"myBundle = $myBundle\n")
    // myBundle = Bundle(a -> 3, b -> 11)

    Users can override the default behavior of .toPrintable in custom Bundle and Record types.

  50. implicit final class PrintableHelper extends AnyVal

    Implicit for custom Printable string interpolator

  51. case class Printables(pables: Iterable[Printable]) extends Printable with Product with Serializable
  52. abstract class RawModule extends BaseModule

    Abstract base class for Modules that contain Chisel RTL.

    Abstract base class for Modules that contain Chisel RTL. This abstract base class is a user-defined module which does not include implicit clock and reset and supports multiple IO() declarations.

  53. case class RebindingException(message: String) extends BindingException with Product with Serializable

    Attempted to re-bind an already bound (directionality or hardware) object

  54. abstract class Record extends Aggregate

    Base class for Aggregates based on key values pairs of String and Data

    Base class for Aggregates based on key values pairs of String and Data

    Record should only be extended by libraries and fairly sophisticated generators. RTL writers should use Bundle. See Record#elements for an example.

  55. trait RequireAsyncReset extends Module

    Enforce that the Module.reset be Asynchronous (AsyncReset)

  56. trait RequireSyncReset extends Module

    Enforce that the Module.reset be Synchronous (Bool)

  57. sealed trait Reset extends Element with ToBoolable
  58. final class ResetType extends Element with Reset

    "Abstract" Reset Type inferred in FIRRTL to either AsyncReset or Bool

    "Abstract" Reset Type inferred in FIRRTL to either AsyncReset or Bool

    Note

    This shares a common interface with AsyncReset and Bool but is not their actual super type due to Bool inheriting from abstract class UInt

  59. sealed class SInt extends Bits with Num[SInt]

    A data type for signed integers, represented as a binary bitvector.

    A data type for signed integers, represented as a binary bitvector. Defines arithmetic operations between other integer types.

  60. trait SIntFactory extends AnyRef
  61. trait SourceInfoDoc extends AnyRef

    Provides ScalaDoc information for "hidden" do_* methods

    Provides ScalaDoc information for "hidden" do_* methods

    Mix this into classes/objects that have do_* methods to get access to the shared SourceInfoTransformMacro ScalaDoc group and the lengthy groupdesc below.

  62. sealed abstract class SpecifiedDirection extends AnyRef

    User-specified directions.

  63. sealed class SyncReadMem[T <: Data] extends MemBase[T]

    A sequential/synchronous-read, sequential/synchronous-write memory.

    A sequential/synchronous-read, sequential/synchronous-write memory.

    Writes take effect on the rising clock edge after the request. Reads return data on the rising edge after the request. Read-after-write behavior (when a read and write to the same address are requested on the same cycle) is undefined.

    Note

    when multiple conflicting writes are performed on a Mem element, the result is undefined (unlike Vec, where the last assignment wins)

  64. sealed class UInt extends Bits with Num[UInt]

    A data type for unsigned integers, represented as a binary bitvector.

    A data type for unsigned integers, represented as a binary bitvector. Defines arithmetic operations between other integer types.

  65. trait UIntFactory extends AnyRef
  66. sealed case class UnknownWidth() extends Width with Product with Serializable
  67. sealed class Vec[T <: Data] extends Aggregate with VecLike[T]

    A vector (array) of Data elements.

    A vector (array) of Data elements. Provides hardware versions of various collection transformation functions found in software array implementations.

    Careful consideration should be given over the use of Vec vs Seq or some other Scala collection. In general Vec only needs to be used when there is a need to express the hardware collection in a Reg or IO Bundle or when access to elements of the array is indexed via a hardware signal.

    Example of indexing into a Vec using a hardware address and where the Vec is defined in an IO Bundle

    val io = IO(new Bundle {
      val in = Input(Vec(20, UInt(16.W)))
      val addr = Input(UInt(5.W))
      val out = Output(UInt(16.W))
    })
    io.out := io.in(io.addr)
    T

    type of elements

    Note

    • when multiple conflicting assignments are performed on a Vec element, the last one takes effect (unlike Mem, where the result is undefined)
    • Vecs, unlike classes in Scala's collection library, are propagated intact to FIRRTL as a vector type, which may make debugging easier
  68. trait VecFactory extends SourceInfoDoc
  69. trait VecLike[T <: Data] extends IndexedSeq[T] with HasId with SourceInfoDoc

    A trait for Vecs containing common hardware generators for collection operations.

  70. trait VerifPrintMacrosDoc extends AnyRef

    Scaladoc information for internal verification statement macros that are used in objects assert, assume and cover.

  71. abstract class VerificationStatement extends NamedComponent

    Base class for all verification statements: Assert, Assume, Cover, Stop and Printf.

  72. final class WhenContext extends AnyRef

    A WhenContext may represent a when, and elsewhen, or an otherwise.

    A WhenContext may represent a when, and elsewhen, or an otherwise. Since FIRRTL does not have an "elsif" statement, alternatives must be mapped to nested if-else statements inside the alternatives of the preceeding condition. In order to emit proper FIRRTL, it is necessary to keep track of the depth of nesting of the FIRRTL whens. Due to the "thin frontend" nature of Chisel3, it is not possible to know if a when or elsewhen has a succeeding elsewhen or otherwise; therefore, this information is added by preprocessing the command queue.

  73. sealed abstract class Width extends AnyRef
  74. trait WireFactory extends AnyRef
  75. implicit class fromBigIntToLiteral extends AnyRef

    These implicit classes allow one to convert scala.Int or scala.BigInt to Chisel.UInt|Chisel.SInt by calling .asUInt|.asSInt on them, respectively.

    These implicit classes allow one to convert scala.Int or scala.BigInt to Chisel.UInt|Chisel.SInt by calling .asUInt|.asSInt on them, respectively. The versions .asUInt(width)|.asSInt(width) are also available to explicitly mark a width for the new literal.

    Also provides .asBool to scala.Boolean and .asUInt to String

    Note that, for stylistic reasons, one should avoid extracting immediately after this call using apply, ie. 0.asUInt(1)(0) due to potential for confusion (the 1 is a bit length and the 0 is a bit extraction position). Prefer storing the result and then extracting from it.

    Implementation note: the empty parameter list (like U()) is necessary to prevent interpreting calls that have a non-Width parameter as a chained apply, otherwise things like 0.asUInt(16) (instead of 16.W) compile without error and produce undesired results.

  76. implicit class fromBooleanToLiteral extends AnyRef
  77. implicit class fromIntToLiteral extends fromBigIntToLiteral
  78. implicit class fromIntToWidth extends AnyRef
  79. implicit class fromLongToLiteral extends fromBigIntToLiteral
  80. implicit class fromStringToLiteral extends AnyRef

Value Members

  1. val Connectable: chisel3.connectable.Connectable.type
  2. final val deprecatedMFCMessage: String("this feature will not be supported as part of the migration to the MLIR-based FIRRTL Compiler (MFC). For more information about this migration, please see the Chisel ROADMAP.md.")
  3. final val deprecatedPublicAPIMsg: String("APIs in chisel3.internal are not intended to be public")
  4. def getDataElements(a: Aggregate): Seq[Element]
  5. implicit def string2Printable(str: String): Printable
  6. object ActualDirection
  7. object AsyncReset
  8. object Bits extends UIntFactory
  9. object Bool extends BoolFactory
  10. case object BuildInfo extends Product with Serializable

    This object was generated by sbt-buildinfo.

  11. object Clock
  12. object Const

    Create a constant type in FIRRTL, which is guaranteed to take a single constant value.

  13. object Data
  14. object Disable
  15. case object DontCare extends Element with ConnectableDocs with Product with Serializable

    RHS (source) for Invalidate API.

    RHS (source) for Invalidate API. Causes connection logic to emit a DefInvalid when connected to an output port (or wire).

  16. object FirrtlFormat
  17. object FlatIO

    The same as IO except there is no prefix when given a Record or Bundle.

    The same as IO except there is no prefix when given a Record or Bundle. For Element (UInt, etc.) or Vec types, this is the same as IO.

    Example:
    1. class MyBundle extends Bundle {
        val foo = Input(UInt(8.W))
        val bar = Output(UInt(8.W))
      }
      class MyModule extends Module {
        val io = FlatIO(new MyBundle)
        // input  [7:0] foo,
        // output [7:0] bar
      }
  18. object Flipped
  19. object HasTarget
  20. object IO
  21. object Input

    Input, Output, and Flipped are used to define the directions of Module IOs.

    Input, Output, and Flipped are used to define the directions of Module IOs.

    Note that they currently clone their source argument, including its bindings.

    Thus, an error will be thrown if these are used on bound Data

  22. object Mem
  23. object Module extends SourceInfoDoc
  24. object Mux extends SourceInfoDoc
  25. object Num extends NumObject
  26. object Output
  27. case object Percent extends Printable with Product with Serializable

    Represents escaped percents

  28. object Printable
  29. object Reg

    Utility for constructing hardware registers

    Utility for constructing hardware registers

    The width of a Reg (inferred or not) is copied from the type template

    val r0 = Reg(UInt()) // width is inferred
    val r1 = Reg(UInt(8.W)) // width is set to 8
    
    val r2 = Reg(Vec(4, UInt())) // width is inferred
    val r3 = Reg(Vec(4, UInt(8.W))) // width of each element is set to 8
    
    class MyBundle {
      val unknown = UInt()
      val known   = UInt(8.W)
    }
    val r4 = Reg(new MyBundle)
    // Width of r4.unknown is inferred
    // Width of r4.known is set to 8
  30. object RegInit

    Utility for constructing hardware registers with an initialization value.

    Utility for constructing hardware registers with an initialization value.

    The register is set to the initialization value when the current implicit reset is high

    The two forms of RegInit differ in how the type and width of the resulting Reg are specified.

    Single Argument

    The single argument form uses the argument to specify both the type and reset value. For non-literal Bits, the width of the Reg will be inferred. For literal Bits and all non-Bits arguments, the type will be copied from the argument. See the following examples for more details:

    1. Literal Bits initializer: width will be set to match

    val r1 = RegInit(1.U) // width will be inferred to be 1
    val r2 = RegInit(1.U(8.W)) // width is set to 8

    2. Non-Literal Element initializer - width will be inferred

    val x = Wire(UInt())
    val y = Wire(UInt(8.W))
    val r1 = RegInit(x) // width will be inferred
    val r2 = RegInit(y) // width will be inferred

    3. Aggregate initializer - width will be set to match the aggregate

    class MyBundle extends Bundle {
      val unknown = UInt()
      val known   = UInt(8.W)
    }
    val w1 = Reg(new MyBundle)
    val w2 = RegInit(w1)
    // Width of w2.unknown is inferred
    // Width of w2.known is set to 8

    Double Argument

    The double argument form allows the type of the Reg and the default connection to be specified independently.

    The width inference semantics for RegInit with two arguments match those of Reg. The first argument to RegInit is the type template which defines the width of the Reg in exactly the same way as the only argument to Wire.

    More explicitly, you can reason about RegInit with multiple arguments as if it were defined as:

    def RegInit[T <: Data](t: T, init: T): T = {
      val x = Reg(t)
      x := init
      x
    }
  31. object RegNext

    Utility for constructing one-cycle delayed versions of signals

    Utility for constructing one-cycle delayed versions of signals

    The width of a RegNext is not set based on the next or init connections for Element types. In the following example, the width of bar will not be set and will be inferred by the FIRRTL compiler.

    val foo = Reg(UInt(4.W))         // width is 4
    val bar = RegNext(foo)           // width is unset

    If you desire an explicit width, do not use RegNext and instead use a register with a specified width:

    val foo = Reg(UInt(4.W))         // width is 4
    val bar = Reg(chiselTypeOf(foo)) // width is 4
    bar := foo

    Also note that a RegNext of a Bundle will have it's width set for Aggregate types.

    class MyBundle extends Bundle {
      val x = UInt(4.W)
    }
    val foo = Wire(new MyBundle)     // the width of foo.x is 4
    val bar = RegNext(foo)           // the width of bar.x is 4
  32. object Reset
  33. object SInt extends SIntFactory
  34. object SpecifiedDirection
  35. object SyncReadMem
  36. object UInt extends UIntFactory
  37. object Vec extends VecFactory
  38. object VecInit extends SourceInfoDoc
  39. object Width
  40. object Wire extends WireFactory

    Utility for constructing hardware wires

    Utility for constructing hardware wires

    The width of a Wire (inferred or not) is copied from the type template

    val w0 = Wire(UInt()) // width is inferred
    val w1 = Wire(UInt(8.W)) // width is set to 8
    
    val w2 = Wire(Vec(4, UInt())) // width is inferred
    val w3 = Wire(Vec(4, UInt(8.W))) // width of each element is set to 8
    
    class MyBundle {
      val unknown = UInt()
      val known   = UInt(8.W)
    }
    val w4 = Wire(new MyBundle)
    // Width of w4.unknown is inferred
    // Width of w4.known is set to 8
  41. object WireDefault extends WireDefaultImpl

    Utility for constructing hardware wires with a default connection

    Utility for constructing hardware wires with a default connection

    The two forms of WireDefault differ in how the type and width of the resulting Wire are specified.

    Single Argument

    The single argument form uses the argument to specify both the type and default connection. For non-literal Bits, the width of the Wire will be inferred. For literal Bits and all non-Bits arguments, the type will be copied from the argument. See the following examples for more details:

    1. Literal Bits initializer: width will be set to match

    val w1 = WireDefault(1.U) // width will be inferred to be 1
    val w2 = WireDefault(1.U(8.W)) // width is set to 8

    2. Non-Literal Element initializer - width will be inferred

    val x = Wire(UInt())
    val y = Wire(UInt(8.W))
    val w1 = WireDefault(x) // width will be inferred
    val w2 = WireDefault(y) // width will be inferred

    3. Aggregate initializer - width will be set to match the aggregate

    class MyBundle {
      val unknown = UInt()
      val known   = UInt(8.W)
    }
    val w1 = Wire(new MyBundle)
    val w2 = WireDefault(w1)
    // Width of w2.unknown is inferred
    // Width of w2.known is set to 8

    Double Argument

    The double argument form allows the type of the Wire and the default connection to be specified independently.

    The width inference semantics for WireDefault with two arguments match those of Wire. The first argument to WireDefault is the type template which defines the width of the Wire in exactly the same way as the only argument to Wire.

    More explicitly, you can reason about WireDefault with multiple arguments as if it were defined as:

    def WireDefault[T <: Data](t: T, init: T): T = {
      val x = Wire(t)
      x := init
      x
    }
  42. object WireInit extends WireDefaultImpl

    Utility for constructing hardware wires with a default connection

    Utility for constructing hardware wires with a default connection

    Alias for WireDefault.

    Note

    The Init in WireInit refers to a "default" connection. This is in contrast to RegInit where the Init refers to a value on reset.

  43. object assert extends VerifPrintMacrosDoc
  44. object assume extends VerifPrintMacrosDoc
  45. object chiselTypeOf

    Returns the chisel type of a hardware object, allowing other hardware to be constructed from it.

  46. object cover extends VerifPrintMacrosDoc
  47. object dontTouch

    Marks that a signal's leaves are an optimization barrier to Chisel and the FIRRTL compiler.

    Marks that a signal's leaves are an optimization barrier to Chisel and the FIRRTL compiler. This has the effect of guaranteeing that a signal will not be removed.

    Example:
    1. class MyModule extends Module {
        val io = IO(new Bundle {
          val a = Input(UInt(32.W))
          val b = Output(UInt(32.W))
        })
        io.b := io.a
        val dead = io.a +% 1.U // normally dead would be pruned by DCE
        dontTouch(dead) // Marking it as such will preserve it
      }
    Note

    Because this is an optimization barrier, constants will not be propagated through a signal's leaves marked as dontTouch.

  48. object emitVerilog
  49. object getVerilogString
  50. object layer

    This object contains Chisel language features for creating layers.

    This object contains Chisel language features for creating layers. Layers are collections of hardware that are not always present in the circuit. Layers are intended to be used to hold verification or debug code.

  51. object printf

    Prints a message in simulation

    Prints a message in simulation

    See apply methods for use

  52. object stop
  53. object suppressEnumCastWarning

    Suppress enum cast warnings

    Suppress enum cast warnings

    Users should use <EnumType>.safe when possible.

    This is primarily used for casting from UInt to a Bundle type that contains an Enum.

    class MyBundle extends Bundle {
      val addr = UInt(8.W)
      val op = OpEnum()
    }
    
    // Since this is a cast to a Bundle, cannot use OpCode.safe
    val bundle = suppressEnumCastWarning {
      someUInt.asTypeOf(new MyBundle)
    }
  54. object when
  55. object withClock
  56. object withClockAndReset
  57. object withDisable

    Creates a new Disable scope

  58. object withReset
  59. object withoutIO

Inherited from AnyRef

Inherited from Any

Ungrouped