== Ports ===========================================================
data in: in
data in: inOp
+ constant NEG: 0
+ constant INC: 1
+ constant DEC: 2
+ constant ABS: 3
data out: out
-== Constants ========================================================
== TeX ==============================================================
+
+{\tt Alu1} is a ``one-input'' arithmetic logic unit. It includes
+logic for performing arithmetic operations on a single argument.
+Currently this includes
+negate ({\sc neg}),
+increment ({\sc inc}),
+decrement ({\sc dec}), and
+absolute value ({\sc abs}).
+
+\subsection*{Semantics}
+
+When a value is present at each of {\tt in} and {\tt inOp}, these two
+values are consumed. Based on the value consumed at {\tt inOp}, the
+requested operation is performed on the value consumed from {\tt in}.
+The result of this operation is then made available at {\tt out}.
+
== Fleeterpreter ====================================================
public void service() {
-/*
- if (in.dataReadyForShip() && op.dataReadyForShip()) {
- int data = in.removeDataForShip();
- int opcode = in.removeDataForShip();
- switch(opcode) {
- case 0: out.addDataFromShip(-1 * data); // NEG
+ if (box_in.dataReadyForShip() && box_inOp.dataReadyForShip() && box_out.readyForDataFromShip()) {
+ long data = box_in.removeDataForShip();
+ long opcode = box_inOp.removeDataForShip();
+ switch((int)opcode) {
+ case 0: box_out.addDataFromShip(-1 * data); // NEG
break;
- case 1: out.addDataFromShip(data+1); // INC
+ case 1: box_out.addDataFromShip(data+1); // INC
break;
- case 2: out.addDataFromShip(data-1); // DEC
+ case 2: box_out.addDataFromShip(data-1); // DEC
break;
- case 3: out.addDataFromShip(Math.abs(data)); // ABS
+ case 3: box_out.addDataFromShip(Math.abs(data)); // ABS
break;
- default: out.addDataFromShip(0);
+ default: box_out.addDataFromShip(0);
break;
}
}
-*/
}
-== ArchSim ==============================================================
+== FleetSim ==============================================================
== FPGA ==============================================================
+ reg have_a;
+ reg [(`PACKET_WIDTH-1):0] reg_a;
+ reg have_op;
+ reg [(`PACKET_WIDTH-1):0] reg_op;
+ reg [(`PACKET_WIDTH-1):0] extrabits;
+
+ always @(posedge clk) begin
+ if (!rst) begin
+ have_a = 0;
+ have_op = 0;
+ `reset
+ end else begin
+ if (!have_a) begin
+ `onread(in_r, in_a) have_a = 1; reg_a = in_d; end
+ end
+ if (!have_op) begin
+ `onread(inOp_r, inOp_a)
+ have_op = 1;
+ reg_op = inOp_d[(`DATAWIDTH-1):0];
+ extrabits = inOp_d[(`PACKET_WIDTH-1):`DATAWIDTH];
+ end
+ end
+
+ if (have_a && have_op) begin
+ case (reg_op)
+ 0: out_d = -reg_a;
+ 1: out_d = reg_a+1;
+ 2: out_d = reg_a-1;
+ 3: out_d = (reg_a<0) ? (-reg_a) : reg_a;
+ 4: out_d = 37'b1111111111111111111111111111111111111;
+ 5: out_d = extrabits;
+ default: out_d = 0;
+ endcase
+ `onwrite(out_r, out_a)
+ have_a = 0;
+ have_op = 0;
+ end
+ end
+ end
+ end
+
+== Test ==============================================================================
+// expected output
+
+#expect 10
+#expect 8
+#expect 9
+#expect -9
+#expect 9
+
+#ship debug : Debug
+#ship alu1 : Alu1
+
+debug.in: [*] take, deliver;
+alu1.in:
+ literal 9;
+ load repeat counter with 4; deliver;
+ take, deliver;
+
+alu1.out:
+ load repeat counter with 4; take, sendto debug.in;
+ sendto alu1.in;
+ take, sendto debug.in;
+
+alu1.inOp:
+ literal 1; deliver;
+ literal 2; deliver;
+ literal 3; deliver;
+ literal 0; deliver;
+ literal 0; deliver;
+
== Contributors =========================================================
Adam Megacz <megacz@cs.berkeley.edu>