BlocksGCU.cc

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/*
    Copyright (c) 2002-2021 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
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/**
 * @file BlocksGCU.cc
 *
 * Implementation of BlocksGCU Class.
 * This class describes the GCU unit of the Blocks (ABU of the TTA).
 *
 * @author Maarten Molendijk 2020 (m.j.molendijk@tue.nl)
 * @author Kanishkan Vadivel 2021 (k.vadivel@tue.nl)
 */
 
#include "BlocksGCU.hh"
 
using namespace TTAMachine;
/**
 * BlocksGCU with default instructions
 *
 * @param mach The TTA machine where the GCU(ABU) needs to be added.
 * @param name The name of the GCU.
 * @param asInstr The address space containing the program instructions.
 */
BlocksGCU::BlocksGCU(
    Machine& mach, const std::string& name, AddressSpace& asInstr) {
    int delaySlots = 2;
    int globalGuardLatency = 1;
    gcu = new ControlUnit(name, delaySlots, globalGuardLatency);
    mach.setGlobalControl(*gcu);
    gcu->setAddressSpace(&asInstr);
 
    // TODO(mm): add check if there is not already a GCU present
    pc = new FUPort("pc", 32, *gcu, true, true, true);
    val = new FUPort("value", 32, *gcu, false, false, true);
    ra = new SpecialRegisterPort("ra", 32, *gcu);
 
    // Create in and ouput sockets for 'special RA port'
    raIn = new Socket("raIn");
    raOut = new Socket("abu_out0");
    valIn = new Socket("value");
    pcIn = new Socket("pc");
    mach.addSocket(*raIn);
    mach.addSocket(*raOut);
    mach.addSocket(*valIn);
    mach.addSocket(*pcIn);
    ra->attachSocket(*raIn);
    ra->attachSocket(*raOut);
    pc->attachSocket(*pcIn);
    val->attachSocket(*valIn);
 
    // Connect in and out socket to bus
    const int busWidth = 32;
    const int immWidth = 0;
    Machine::Extension busExt = Machine::Extension::ZERO;
    Bus* raBus = new Bus("ra_out_to_ra_in", busWidth, immWidth, busExt);
    mach.addBus(*raBus);
    new UnconditionalGuard(false, *raBus);
    new Segment("seg1", *raBus);
    raIn->attachBus(*raBus);
    raOut->attachBus(*raBus);
    pcIn->attachBus(*raBus);
    raOut->setDirection(Socket::Direction::OUTPUT);
 
    // set RA port
    gcu->setReturnAddressPort(*ra);
 
    // Add HWops
    ops.push_back(CreateHWOp("bnz", 2));
    ops.push_back(CreateHWOp("bz", 2));
    ops.push_back(CreateHWOp("call", 1));
    ops.push_back(CreateHWOp("jump", 1));
}
 
/**
 * Configure the operation pipeline.
 *
 * @param pipeline A pointer to the execution pipeline of the operation of
 * which the pipeline needs to be configured.
 * @param numOfOperands The number of operands of the given hwOp.
 */
void
BlocksGCU::ConfigurePipeline(
    TTAMachine::ExecutionPipeline* pipeline, int numOfOperands) {
    if (numOfOperands == 1) {
        pipeline->addPortRead(1, 0, 1);
    } else if (numOfOperands == 2) {
        pipeline->addPortRead(1, 0, 1);
        pipeline->addPortRead(2, 0, 1);
    } else {
        // Currently no operation known that uses a different numbers of
        // operands.
        assert(
            false &&
            "Trying to add a GCU operation with a different number of "
            "operands than 1 or 2.");
    }
}
 
/**
 * Bind the operation's operands to GCU ports.
 *
 * @param hwOp A pointer to the hardware operation of which the operands need
 * to be binded to GCU ports.
 * @param numOfOperands The number of operands of the given hwOp.
 */
void
BlocksGCU::BindPorts(TTAMachine::HWOperation* hwOp, int numOfOperands) {
    if (numOfOperands < 2) {
        hwOp->bindPort(1, *pc);
    } else {
        hwOp->bindPort(2, *pc);  // Program counter is operand 2, therfore
                                 // port binding is switched.
        hwOp->bindPort(1, *val);
    }
}
 
/**
 * Creates a hardware operation.
 *
 * @param name The name of the hardware operation. This needs to exactly match
 * the name in OSEd.
 * @param numOfOperands The number of operands that this hardware operation
 * requires.
 */
HWOperation*
BlocksGCU::CreateHWOp(const std::string& name, int numOfOperands) {
    HWOperation* op = new HWOperation(name, *gcu);
    BindPorts(op, numOfOperands);
    ConfigurePipeline(op->pipeline(), numOfOperands);
    return op;
}