import debug
import design
import utils
from tech import GDS,layer

class tri_gate(design.design):
    """
    This module implements the tri gate cell used in the design for
    bit-line isolation. It is a hand-made cell, so the layout and
    netlist should be available in the technology library.  
    """

    pin_names = ["in", "en", "en_bar", "out", "gnd", "vdd"]
    (width,height) = utils.get_libcell_size("tri_gate", GDS["unit"], layer["boundary"])
    pin_map = utils.get_libcell_pins(pin_names, "tri_gate", GDS["unit"], layer["boundary"])

    unique_id = 1
    
    def __init__(self, name=""):
        if name=="":
            name = "tri{0}".format(tri_gate.unique_id)
            tri_gate.unique_id += 1
        design.design.__init__(self, name)
        debug.info(2, "Create tri_gate")

        self.width = tri_gate.width
        self.height = tri_gate.height
        self.pin_map = tri_gate.pin_map

    def analytical_delay(self, slew, load=0.0):
        from tech import spice
        r = spice["min_tx_r"]
        c_para = spice["min_tx_drain_c"]
        return self.cal_delay_with_rc(r = r, c =  c_para+load, slew = slew)


    def input_load(self):
        return 9*spice["min_tx_gate_c"]