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WIP, Use nextIndexSelector with Key buffer #35

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WIP, Use nextIndexSelector with Key buffer #35

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27 changes: 18 additions & 9 deletions src/main/scala/KeyBuffer.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -5,14 +5,18 @@ import chisel3.util._


class KeyBufferIO(busWidth: Int, numberOfBuffers: Int) extends Bundle {
// Inputs from KV Transfer module
val enq = Flipped(Decoupled(UInt(busWidth.W)))
val deq = Decoupled(UInt(busWidth.W))

val bufferInputSelect = Input(UInt(log2Ceil(numberOfBuffers).W))
val incrWritePtr = Input(Bool())
val clearBuffer = Input(Bool())
val lastInput = Input(Bool())

// Control inputs from KV Transfer module
val clearBuffer = Input(Bool())
val mask = Input(UInt(numberOfBuffers.W))

// Outputs to Merger module
val deq = Decoupled(UInt(busWidth.W))
val bufferOutputSelect = Output(UInt(log2Ceil(numberOfBuffers).W))
val empty = Output(Bool())
val lastOutput = Output(Bool())
Expand Down Expand Up @@ -52,6 +56,7 @@ class KeyBuffer(busWidth: Int, numberOfBuffers: Int, maximumKeySize: Int) extend
val stateReg = RegInit(idle)
val shadowReg = RegInit(0.U(busWidth.W))

val mask = RegInit(0.U(numberOfBuffers.W))
val bufferOutputSelect = RegInit(0.U(log2Ceil(numberOfBuffers).W))

val shouldIncreaseReadPtr = bufferOutputSelect === (numberOfBuffers-1).U
Expand Down Expand Up @@ -80,13 +85,17 @@ class KeyBuffer(busWidth: Int, numberOfBuffers: Int, maximumKeySize: Int) extend
}
}

val nextIndexSelector = Module(new NextIndexSelector(numberOfBuffers))
nextIndexSelector.io.mask := io.mask
nextIndexSelector.io.currentIndex := bufferOutputSelect

when (io.clearBuffer) {
stateReg := idle
emptyReg := true.B
fullReg := false.B
writePtr := 0.U
readPtr := 0.U
bufferOutputSelect := 0.U
bufferOutputSelect := PriorityEncoder(io.mask)
lastChunks.foreach(_ := false.B)
lastChunkCounters.foreach(_ := 0.U)
}
Expand All @@ -100,7 +109,7 @@ class KeyBuffer(busWidth: Int, numberOfBuffers: Int, maximumKeySize: Int) extend
fullReg := false.B
emptyReg := nextRead === writePtr && shouldIncreaseReadPtr && !io.incrWritePtr
// prepare for the next read, as it requires one cycle delay
bufferOutputSelect := bufferOutputSelect + 1.U
bufferOutputSelect := nextIndexSelector.io.nextIndex
}
}
is(valid) {
Expand All @@ -111,9 +120,9 @@ class KeyBuffer(busWidth: Int, numberOfBuffers: Int, maximumKeySize: Int) extend
fullReg := false.B
emptyReg := nextRead === writePtr && shouldIncreaseReadPtr && !io.incrWritePtr
incrRead := shouldIncreaseReadPtr
bufferOutputSelect := bufferOutputSelect + 1.U
bufferOutputSelect := nextIndexSelector.io.nextIndex
} otherwise {
bufferOutputSelect := 0.U
bufferOutputSelect := nextIndexSelector.io.nextIndex
stateReg := idle
}
} otherwise {
Expand All @@ -130,9 +139,9 @@ class KeyBuffer(busWidth: Int, numberOfBuffers: Int, maximumKeySize: Int) extend
fullReg := false.B
emptyReg := nextRead === writePtr && shouldIncreaseReadPtr && !io.incrWritePtr
incrRead := shouldIncreaseReadPtr
bufferOutputSelect := bufferOutputSelect + 1.U
bufferOutputSelect := nextIndexSelector.io.nextIndex
} otherwise {
bufferOutputSelect := 0.U
bufferOutputSelect := nextIndexSelector.io.nextIndex
stateReg := idle
}
}
Expand Down
30 changes: 30 additions & 0 deletions src/test/scala/KeyBufferSpec.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,12 @@ class KeyBufferSpec extends AnyFreeSpec with ChiselScalatestTester {
dut.io.enq.valid.poke(true.B)
dut.io.incrWritePtr.poke(false.B)
dut.io.lastInput.poke(false.B)
dut.io.mask.poke("b1111".U)

// clear key buffer before loading
dut.io.clearBuffer.poke(true.B)
dut.clock.step()
dut.io.clearBuffer.poke(false.B)

// Write two rows of key chunks
for (i <- 0 until 4) {
Expand Down Expand Up @@ -111,6 +117,12 @@ class KeyBufferSpec extends AnyFreeSpec with ChiselScalatestTester {
dut.io.enq.valid.poke(true.B)
dut.io.incrWritePtr.poke(false.B)
dut.io.lastInput.poke(false.B)
dut.io.mask.poke("b1111".U)

// clear key buffer before loading
dut.io.clearBuffer.poke(true.B)
dut.clock.step()
dut.io.clearBuffer.poke(false.B)

// Write first row of key chunks
for (i <- 0 until 4) {
Expand Down Expand Up @@ -213,6 +225,12 @@ class KeyBufferSpec extends AnyFreeSpec with ChiselScalatestTester {
dut.io.incrWritePtr.poke(false.B)
dut.io.empty.expect(true.B)
dut.io.lastInput.poke(false.B)
dut.io.mask.poke("b1111".U)

// clear key buffer before loading
dut.io.clearBuffer.poke(true.B)
dut.clock.step()
dut.io.clearBuffer.poke(false.B)

// Write one row of key chunks
for (i <- 0 until 4) {
Expand Down Expand Up @@ -284,6 +302,12 @@ class KeyBufferSpec extends AnyFreeSpec with ChiselScalatestTester {
dut.io.deq.ready.poke(false.B)
dut.io.enq.valid.poke(true.B)
dut.io.incrWritePtr.poke(false.B)
dut.io.mask.poke("b1111".U)

// clear key buffer before loading
dut.io.clearBuffer.poke(true.B)
dut.clock.step()
dut.io.clearBuffer.poke(false.B)

// Write one row of key chunks
for (i <- 0 until 4) {
Expand Down Expand Up @@ -316,6 +340,12 @@ class KeyBufferSpec extends AnyFreeSpec with ChiselScalatestTester {
dut.io.deq.ready.poke(false.B)
dut.io.enq.valid.poke(true.B)
dut.io.lastInput.poke(false.B)
dut.io.mask.poke("b1111".U)

// clear key buffer before loading
dut.io.clearBuffer.poke(true.B)
dut.clock.step()
dut.io.clearBuffer.poke(false.B)

// Write first row of key chunks
for (i <- 0 until 4) {
Expand Down