AssignmentQueue.icc

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/*
    Copyright (c) 2002-2009 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
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    The above copyright notice and this permission notice shall be included in
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    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 */
 
/**
 * Adds a new delayed assignment to the queue
 * 
 * @param assignValue value to be assigned
 * @param assignTarget pointer to the target of the assignment
 * @param latency how long to wait in the queue until assignment can be done
 * @note if the latency is zero, the assignment is done immediately
 */
void inline
AssignmentQueue::addAssignment(
    const SimValue& assignValue, SimValue* assignTarget, int latency) {
    
    if (maxLatency_ == 0) { // ring buffer with a size of zero! do nothing.
        return;
    }
    
    assert(latency >= 0  && latency <= maxLatency_);
    
    if (latency == 0) {
        (*assignTarget) = assignValue;
        return;
    }
    
    int location = (position_ + latency) % maxLatency_;
    assignmentQueue_[location].push_back(
        Assignment(assignValue, assignTarget));
}
 
/**
 * Advances the assign queue by one cycle.
 * 
 * Reduces delayed assignments wait time by one
 */
void inline
AssignmentQueue::advanceClock() {
    
    if (maxLatency_ == 0) { // ring buffer with a size of zero! do nothing.
        return;
    }
    
    // Move to the next position in the ring buffer
    position_ = (position_ + 1) % maxLatency_;
    
    while (!assignmentQueue_[position_].empty()) {        
        // do the assignment and remove it
        Assignment& a = assignmentQueue_[position_].front();
        (*a.second) = a.first;
        assignmentQueue_[position_].pop_front();
    }
}