50 lines
1.2 KiB
Scala
50 lines
1.2 KiB
Scala
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package utils
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import chisel3._
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import chisel3.util._
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class CircularQueuePtr(val entries: Int) extends Bundle {
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val PTR_WIDTH = log2Up(entries)
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val flag = Bool()
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val value = UInt(PTR_WIDTH.W)
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}
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trait HasCircularQueuePtrHelper {
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implicit class QueuePtrHelper[T <: CircularQueuePtr](ptr: T) {
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final def +(v: UInt): T = {
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val entries = ptr.entries
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val new_ptr = Wire(ptr.cloneType)
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if(isPow2(entries)){
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new_ptr := (Cat(ptr.flag, ptr.value) + v).asTypeOf(new_ptr)
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} else {
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val new_value = ptr.value +& v
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val diff = Cat(0.U(1.W), new_value).asSInt() - Cat(0.U(1.W), (entries-1).U).asSInt()
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val reverse_flag = diff > 0.S
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new_ptr.flag := Mux(reverse_flag, !ptr.flag, ptr.flag)
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new_ptr.value := Mux(reverse_flag,
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diff.asUInt(),
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new_value
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)
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}
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new_ptr
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}
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final def === (that_ptr: T): Bool = ptr.asUInt()===that_ptr.asUInt()
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}
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def isEmpty[T <: CircularQueuePtr](enq_ptr: T, deq_ptr: T): Bool = {
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enq_ptr === deq_ptr
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}
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def isFull[T <: CircularQueuePtr](enq_ptr: T, deq_ptr: T): Bool = {
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(enq_ptr.flag =/= deq_ptr.flag) && (enq_ptr.value === deq_ptr.value)
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}
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}
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