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/*****************************************************************************
Licensed to Accellera Systems Initiative Inc. (Accellera) under one or
more contributor license agreements. See the NOTICE file distributed
with this work for additional information regarding copyright ownership.
Accellera licenses this file to you under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with the
License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied. See the License for the specific language governing
permissions and limitations under the License.
*****************************************************************************/
/*****************************************************************************
exec.cpp -- Integer Execution Unit.
Original Author: Martin Wang, Synopsys, Inc.
*****************************************************************************/
/*****************************************************************************
MODIFICATION LOG - modifiers, enter your name, affiliation, date and
changes you are making here.
Name, Affiliation, Date:
Description of Modification:
*****************************************************************************/
#include "systemc.h"
#include "exec.h"
#include "directive.h"
void exec::entry(){
int opcode_tmp = 0;
int add1_tmp = 0;
signed int dina_tmp = 0;
signed int dinb_tmp = 0;
sc_dt::int64 dout_tmp = 0;
unsigned int dest_tmp = 0;
//
// main loop
//
//
// initialization of output
wait(3);
while(1) {
if (in_valid.read() == true) {
dina_tmp = dina.read();
dinb_tmp = dinb.read();
opcode_tmp = opcode.read();
dest_tmp = dest.read();
// output MUX
switch (opcode_tmp) {
case 0: // Stall
// dout_tmp = dout_tmp; // keeps its value
wait();
break;
case 1: // add with carry
dout_tmp = dina_tmp + dinb_tmp + add1_tmp;
wait();
break;
case 2: // sub with carry
dout_tmp = dina_tmp - dinb_tmp - add1_tmp;
wait();
break;
case 3: // add without carry
dout_tmp = dina_tmp + dinb_tmp;
wait();
break;
case 4: // sub without carry
dout_tmp = dina_tmp - dinb_tmp;
wait();
break;
case 5: // multiply assume 2 clock cycle multiplication
dout_tmp = dina_tmp * dinb_tmp;
wait(); // so that BC has something to do
wait();
break;
case 6: // divide assume 2 clock cycle division
if (dinb_tmp == 0) {
printf("Division Exception - Divide by zero \n");
} else {
dout_tmp = dina_tmp / dinb_tmp;
}
wait(); // so that BC has something to do
wait();
break;
case 7: // bitwise NAND
dout_tmp = ~(dina_tmp & dinb_tmp);
wait();
break;
case 8: // bitwise AND
dout_tmp = dina_tmp & dinb_tmp;
wait();
break;
case 9: // bitwise OR
dout_tmp = dina_tmp | dinb_tmp;
wait();
break;
case 10: // bitwise XOR
dout_tmp = dina_tmp ^ dinb_tmp;
wait();
break;
case 11: // bitwise complement
dout_tmp = ~ dina_tmp;
wait();
break;
case 12: // left shift
dout_tmp = dina_tmp << dinb_tmp;
wait();
break;
case 13: // right shift
dout_tmp = dina_tmp >> dinb_tmp;
wait();
break;
case 14: // modulo
dout_tmp = dina_tmp % dinb_tmp;
wait();
break;
default:
printf("ALU: Bad Opcode %d.\n",opcode_tmp);
break;
}
dout.write(static_cast<signed int>(dout_tmp));
out_valid.write(true);
destout.write(dest_tmp);
if (dout_tmp == 0) {
Z.write(true);
} else {
Z.write(false);
}
sc_dt::int64 abs_dout = dout_tmp >= 0 ? dout_tmp : -dout_tmp;
const sc_dt::int64 carry_mask = sc_dt::int64(1) << 32;
if (abs_dout & carry_mask) {
C.write(true);
} else {
C.write(false);
}
if (abs_dout > carry_mask) {
V.write(true);
} else {
V.write(false);
}
printf("\t\t\t\t\t\t\t-------------------------------\n");
cout << "\t\t\t\t\t\t\tALU :" << " op= " << opcode_tmp
<< " A= " << dina_tmp << " B= " << dinb_tmp << endl;
cout << "\t\t\t\t\t\t\tALU :" << " R= " << dout_tmp << "-> R" << dest_tmp;
cout << " at CSIM " << sc_time_stamp() << endl;
printf("\t\t\t\t\t\t\t-------------------------------\n");
wait();
out_valid.write(false);
wait();
} else {
wait();
}
}
}
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