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secondorderdirectformiir_architecture.py 3.21 KiB
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  • =========================================
    Second-order IIR Filter with Architecture
    =========================================
    
    
    """
    
    from b_asic.architecture import Architecture, Memory, ProcessingElement
    from b_asic.core_operations import Addition, ConstantMultiplication
    from b_asic.schedule import Schedule
    
    from b_asic.scheduler import ASAPScheduler
    
    from b_asic.signal_flow_graph import SFG
    from b_asic.special_operations import Delay, Input, Output
    
    in1 = Input("IN1")
    c0 = ConstantMultiplication(5, in1, "C0")
    add1 = Addition(c0, None, "ADD1")
    T1 = Delay(add1, 0, "T1")
    T2 = Delay(T1, 0, "T2")
    b2 = ConstantMultiplication(0.2, T2, "B2")
    b1 = ConstantMultiplication(0.3, T1, "B1")
    add2 = Addition(b1, b2, "ADD2")
    add1.input(1).connect(add2)
    a1 = ConstantMultiplication(0.4, T1, "A1")
    a2 = ConstantMultiplication(0.6, T2, "A2")
    add3 = Addition(a1, a2, "ADD3")
    a0 = ConstantMultiplication(0.7, add1, "A0")
    add4 = Addition(a0, add3, "ADD4")
    out1 = Output(add4, "OUT1")
    
    sfg = SFG(inputs=[in1], outputs=[out1], name="Second-order direct form IIR filter")
    
    # %%
    
    # The SFG is
    sfg
    
    # %%
    # Set latencies and execution times.
    
    sfg.set_latency_of_type(ConstantMultiplication.type_name(), 2)
    sfg.set_latency_of_type(Addition.type_name(), 1)
    sfg.set_execution_time_of_type(ConstantMultiplication.type_name(), 1)
    sfg.set_execution_time_of_type(Addition.type_name(), 1)
    
    # %%
    
    # Create schedule.
    
    schedule = Schedule(sfg, scheduler=ASAPScheduler(), cyclic=True)
    
    schedule.show(title='Original schedule')
    
    # Reschedule to only require one adder and one multiplier.
    
    schedule.move_operation('add3', 2)
    schedule.move_operation('cmul4', -4)
    schedule.move_operation('cmul3', -5)
    schedule.move_operation('cmul5', -2)
    schedule.move_operation('cmul2', 1)
    
    schedule.show(title='Improved schedule')
    
    # Extract operations and create processing elements.
    
    operations = schedule.get_operations()
    adders = operations.get_by_type_name('add')
    
    adders.show(title="Adder executions")
    
    mults = operations.get_by_type_name('cmul')
    
    mults.show(title="Multiplier executions")
    
    inputs = operations.get_by_type_name('in')
    
    inputs.show(title="Input executions")
    
    outputs = operations.get_by_type_name('out')
    
    outputs.show(title="Output executions")
    
    adder = ProcessingElement(adders, entity_name="adder")
    multiplier = ProcessingElement(mults, entity_name="multiplier")
    pe_in = ProcessingElement(inputs, entity_name='input')
    pe_out = ProcessingElement(outputs, entity_name='output')
    
    # Extract and assign memory variables.
    
    mem_vars = schedule.get_memory_variables()
    
    mem_vars.show(title="All memory variables")
    
    direct, mem_vars = mem_vars.split_on_length()
    
    mem_vars.show(title="Non-zero time memory variables")
    
    mem_vars_set = mem_vars.split_on_ports(read_ports=1, write_ports=1, total_ports=2)
    
    memories = []
    
    for i, mem in enumerate(mem_vars_set):
    
        memory = Memory(mem, memory_type="RAM", entity_name=f"memory{i}")
        memories.append(memory)
        mem.show(title=f"{memory.entity_name}")
        memory.assign("left_edge")
        memory.show_content(title=f"Assigned {memory.entity_name}")
    
    direct.show(title="Direct interconnects")
    
    # Create architecture.
    arch = Architecture(
        {adder, multiplier, pe_in, pe_out}, memories, direct_interconnects=direct
    )
    
    
    # %%
    # The architecture can be rendered in enriched shells.