== Constants ========================================================
ADD: add the two arguments; treat link as carry
SUB: subtract the two arguments; treat link as carry
-REM:
MAX:
MIN:
-SORT: output min(in1,in2) followed by max(in1,in2) (FIXME: redundant?)
== TeX ==============================================================
This ship is a two-input arithmetic unit. It features several
Use carry-in bit to create a selector? Perhaps a waste of an ALU.
-Carry-save / carry completion stuff.
-
Flags: zero, negative, overflow, ?
move elsewhere:
//MOD:
== Fleeterpreter ====================================================
+public long resolveLiteral(String literal) {
+ if (literal.equals("ADD")) return 0;
+ if (literal.equals("SUB")) return 1;
+ if (literal.equals("MAX")) return 2;
+ if (literal.equals("MIN")) return 3;
+ return super.resolveLiteral(literal);
+}
public void service() {
if (box_in1.dataReadyForShip() &&
box_in2.dataReadyForShip() &&
box_inOp.dataReadyForShip() &&
- box_out.readyForItemFromShip()) {
- int a = box_in1.removeDataForShip();
- int b = box_in2.removeDataForShip();
- int op = box_inOp.removeDataForShip();
- switch(op) {
+ box_out.readyForDataFromShip()) {
+ long a = box_in1.removeDataForShip();
+ long b = box_in2.removeDataForShip();
+ long op = box_inOp.removeDataForShip();
+ switch((int)op) {
case 0: box_out.addDataFromShip(a+b); // ADD
break;
case 1: box_out.addDataFromShip(a-b); // SUB
break;
+ case 2: box_out.addDataFromShip(Math.max(a,b)); // MAX
+ break;
+ case 3: box_out.addDataFromShip(Math.min(a,b)); // MIN
+ break;
default: box_out.addDataFromShip(0);
break;
}
== FPGA ==============================================================
- input clk;
- `input(in1_r, in1_a, in1_a_, [(`DATAWIDTH-1):0], in1_d)
- `input(in2_r, in2_a, in2_a_, [(`DATAWIDTH-1):0], in2_d)
- `input(inOp_r, inOp_a, inOp_a_, [(`DATAWIDTH-1):0], inOp_d)
- `output(out_r, out_r_, out_a, [(`DATAWIDTH-1):0], out_d_)
-
- `defreg(out_d_, [(`DATAWIDTH-1):0], out_d)
-
reg have_a;
reg [(`DATAWIDTH-1):0] reg_a;
reg have_b;
case (reg_op)
0: out_d = reg_a + reg_b;
1: out_d = reg_a - reg_b;
- //2: out_d = reg_a * reg_b; // will not synthesize --AM
- //3: out_d = reg_a / reg_b; // will not synthesize --AM
- //4: out_d = reg_a % reg_b; // will not synthesize --AM
+ 2: out_d = reg_a > reg_b ? reg_a : reg_b;
+ 3: out_d = reg_a > reg_b ? reg_b : reg_a;
default: out_d = 0;
endcase
`onwrite(out_r, out_a)
end
end
-endmodule