diff --git a/compiler/modules/hierarchical_decoder.py b/compiler/modules/hierarchical_decoder.py index be062acf..0e5b3606 100644 --- a/compiler/modules/hierarchical_decoder.py +++ b/compiler/modules/hierarchical_decoder.py @@ -32,11 +32,11 @@ class hierarchical_decoder(design.design): self.cell_multiple = cell_properties.bitcell.decoder_bitcell_multiple except AttributeError: self.cell_multiple = 1 + # For debugging + # self.cell_multiple = 2 self.cell_height = self.cell_multiple * b.height self.num_outputs = num_outputs - # We may have more than one bitcell per decoder row - self.rows = math.ceil(num_outputs / self.cell_multiple) self.num_inputs = math.ceil(math.log(self.num_outputs, 2)) (self.no_of_pre2x4, self.no_of_pre3x8)=self.determine_predecodes(self.num_inputs) @@ -51,6 +51,10 @@ class hierarchical_decoder(design.design): because a DRC tool would be required even to run in front-end mode. """ b = factory.create(module_type="bitcell") + + # Old behavior + if OPTS.netlist_only: + return (b.height, 1) # Search for the smallest multiple that works cell_multiple = 1 @@ -86,8 +90,8 @@ class hierarchical_decoder(design.design): self.setup_layout_constants() self.place_pre_decoder() self.place_row_decoder() - self.route_input_rails() - self.route_predecode_rails() + self.route_inputs() + self.route_decoder_bus() self.route_vdd_gnd() self.offset_all_coordinates() self.add_boundary() @@ -141,7 +145,7 @@ class hierarchical_decoder(design.design): def setup_netlist_constants(self): self.predec_groups = [] # This array is a 2D array. - # Distributing vertical rails to different groups. One group belongs to one pre-decoder. + # Distributing vertical bus to different groups. One group belongs to one pre-decoder. # For example, for two 2:4 pre-decoder and one 3:8 pre-decoder, we will # have total 16 output lines out of these 3 pre-decoders and they will # be distributed as [ [0,1,2,3] ,[4,5,6,7], [8,9,10,11,12,13,14,15] ] @@ -180,39 +184,45 @@ class hierarchical_decoder(design.design): self.predecoder_height = self.pre2_4.height * self.no_of_pre2x4 + self.pre3_8.height * self.no_of_pre3x8 + # We may have more than one bitcell per decoder row + self.num_rows = math.ceil(self.num_outputs / self.cell_multiple) + # We will place this many final decoders per row + self.decoders_per_row = math.ceil(self.num_outputs / self.num_rows) + # Calculates height and width of row-decoder if (self.num_inputs == 4 or self.num_inputs == 5): nand_width = self.and2.width else: nand_width = self.and3.width - self.internal_routing_width = self.m2_pitch * self.total_number_of_predecoder_outputs - self.row_decoder_height = self.inv.height * self.rows + self.internal_routing_width = self.m2_pitch * (self.total_number_of_predecoder_outputs + 1) + self.row_decoder_height = self.inv.height * self.num_rows self.input_routing_width = (self.num_inputs + 1) * self.m2_pitch # Calculates height and width of hierarchical decoder - self.height = self.row_decoder_height + self.height = max(self.predecoder_height, self.row_decoder_height) self.width = self.input_routing_width + self.predecoder_width \ - + self.internal_routing_width + nand_width + self.inv.width + + self.internal_routing_width \ + + self.decoders_per_row * nand_width + self.inv.width - def route_input_rails(self): - """ Create input rails for the predecoders """ + def route_inputs(self): + """ Create input bus for the predecoders """ # inputs should be as high as the decoders input_height = self.no_of_pre2x4 * self.pre2_4.height + self.no_of_pre3x8 * self.pre3_8.height # Find the left-most predecoder min_x = 0 if self.no_of_pre2x4 > 0: - min_x = min(min_x, -self.pre2_4.width) + min_x = min(min_x, self.pre2x4_inst[0].lx()) if self.no_of_pre3x8 > 0: - min_x = min(min_x, -self.pre3_8.width) + min_x = min(min_x, self.pre3x8_inst[0].lx()) input_offset=vector(min_x - self.input_routing_width, 0) input_bus_names = ["addr_{0}".format(i) for i in range(self.num_inputs)] - self.input_rails = self.create_vertical_pin_bus(layer="m2", - pitch=self.m2_pitch, - offset=input_offset, - names=input_bus_names, - length=input_height) + self.input_bus = self.create_vertical_pin_bus(layer="m2", + pitch=self.m2_pitch, + offset=input_offset, + names=input_bus_names, + length=input_height) self.route_input_to_predecodes() @@ -222,7 +232,7 @@ class hierarchical_decoder(design.design): for i in range(2): index = pre_num * 2 + i - input_pos = self.input_rails["addr_{}".format(index)] + input_pos = self.input_bus["addr_{}".format(index)] in_name = "in_{}".format(i) decoder_pin = self.pre2x4_inst[pre_num].get_pin(in_name) @@ -232,13 +242,13 @@ class hierarchical_decoder(design.design): decoder_offset = decoder_pin.bc() + vector(0, (i + 1) * self.inv.height) input_offset = input_pos.scale(1, 0) + decoder_offset.scale(0, 1) - self.route_input_rail(decoder_offset, input_offset) + self.route_input_bus(decoder_offset, input_offset) for pre_num in range(self.no_of_pre3x8): for i in range(3): index = pre_num * 3 + i + self.no_of_pre2x4 * 2 - input_pos = self.input_rails["addr_{}".format(index)] + input_pos = self.input_bus["addr_{}".format(index)] in_name = "in_{}".format(i) decoder_pin = self.pre3x8_inst[pre_num].get_pin(in_name) @@ -248,9 +258,9 @@ class hierarchical_decoder(design.design): decoder_offset = decoder_pin.bc() + vector(0, (i + 1) * self.inv.height) input_offset = input_pos.scale(1, 0) + decoder_offset.scale(0, 1) - self.route_input_rail(decoder_offset, input_offset) + self.route_input_bus(decoder_offset, input_offset) - def route_input_rail(self, input_offset, output_offset): + def route_input_bus(self, input_offset, output_offset): """ Route a vertical M2 coordinate to another vertical M2 coordinate to the predecode inputs """ self.add_via_center(layers=self.m2_stack, @@ -334,18 +344,17 @@ class hierarchical_decoder(design.design): else: base= vector(-self.pre2_4.width, num * self.pre2_4.height) - self.pre2x4_inst[num].place(base) + self.pre2x4_inst[num].place(base - vector(2 * self.m2_pitch, 0)) def place_pre3x8(self, num): """ Place 3x8 predecoder to the left of the origin and above any 2x4 decoders """ if (self.num_inputs == 3): offset = vector(-self.pre_3_8.width, 0) - mirror = "R0" else: height = self.no_of_pre2x4 * self.pre2_4.height + num * self.pre3_8.height offset = vector(-self.pre3_8.width, height) - self.pre3x8_inst[num].place(offset) + self.pre3x8_inst[num].place(offset - vector(2 * self.m2_pitch, 0)) def create_row_decoder(self): """ Create the row-decoder by placing AND2/AND3 and Inverters @@ -362,14 +371,14 @@ class hierarchical_decoder(design.design): if (self.num_inputs == 4 or self.num_inputs == 5): for i in range(len(self.predec_groups[0])): for j in range(len(self.predec_groups[1])): - row = len(self.predec_groups[0]) * j + i - if (row < self.num_outputs): - name = self.AND_FORMAT.format(row) + output = len(self.predec_groups[0]) * j + i + if (output < self.num_outputs): + name = self.AND_FORMAT.format(output) self.and_inst.append(self.add_inst(name=name, mod=self.and2)) pins =["out_{0}".format(i), "out_{0}".format(j + len(self.predec_groups[0])), - "decode_{0}".format(row), + "decode_{0}".format(output), "vdd", "gnd"] self.connect_inst(pins) @@ -378,18 +387,18 @@ class hierarchical_decoder(design.design): for i in range(len(self.predec_groups[0])): for j in range(len(self.predec_groups[1])): for k in range(len(self.predec_groups[2])): - row = (len(self.predec_groups[0]) * len(self.predec_groups[1])) * k \ - + len(self.predec_groups[0]) * j + i + output = (len(self.predec_groups[0]) * len(self.predec_groups[1])) * k \ + + len(self.predec_groups[0]) * j + i - if (row < self.num_outputs): - name = self.AND_FORMAT.format(row) + if (output < self.num_outputs): + name = self.AND_FORMAT.format(output) self.and_inst.append(self.add_inst(name=name, mod=self.and3)) pins = ["out_{0}".format(i), "out_{0}".format(j + len(self.predec_groups[0])), "out_{0}".format(k + len(self.predec_groups[0]) + len(self.predec_groups[1])), - "decode_{0}".format(row), + "decode_{0}".format(output), "vdd", "gnd"] self.connect_inst(pins) @@ -403,7 +412,10 @@ class hierarchical_decoder(design.design): self.route_decoder() def place_decoder_and_array(self): - """ Add a column of AND gates for final decode """ + """ + Add a column of AND gates for final decode. + This may have more than one decoder per row to match the bitcell height. + """ # Row Decoder AND GATE array for address inputs <5. if (self.num_inputs == 4 or self.num_inputs == 5): @@ -415,9 +427,13 @@ class hierarchical_decoder(design.design): self.place_and_array(and_mod=self.and3) def place_and_array(self, and_mod): - """ Add a column of AND gates for the decoder above the predecoders.""" - - for row in range(self.num_outputs): + """ + Add a column of AND gates for the decoder above the predecoders. + """ + + for inst_index in range(self.num_outputs): + row = math.floor(inst_index / self.decoders_per_row) + dec = inst_index % self.decoders_per_row if ((row % 2) == 0): y_off = and_mod.height * row mirror = "R0" @@ -425,46 +441,52 @@ class hierarchical_decoder(design.design): y_off = and_mod.height * (row + 1) mirror = "MX" - self.and_inst[row].place(offset=[self.internal_routing_width, y_off], - mirror=mirror) + x_off = self.internal_routing_width + dec * and_mod.width + self.and_inst[inst_index].place(offset=vector(x_off, y_off), + mirror=mirror) def route_decoder(self): """ Add the pins. """ - for row in range(self.num_outputs): - z_pin = self.and_inst[row].get_pin("Z") - self.add_layout_pin(text="decode_{0}".format(row), + for output in range(self.num_outputs): + z_pin = self.and_inst[output].get_pin("Z") + self.add_layout_pin(text="decode_{0}".format(output), layer="m1", offset=z_pin.ll(), width=z_pin.width(), height=z_pin.height()) - def route_predecode_rails(self): - """ Creates vertical metal 2 rails to connect predecoder and decoder stages.""" + def route_decoder_bus(self): + """ + Creates vertical metal 2 bus to connect predecoder and decoder stages. + """ # This is not needed for inputs <4 since they have no pre/decode stages. if (self.num_inputs >= 4): - input_offset = vector(0.5 * self.m2_width, 0) + # This leaves an offset for the predecoder output jogs input_bus_names = ["predecode_{0}".format(i) for i in range(self.total_number_of_predecoder_outputs)] - self.predecode_rails = self.create_vertical_pin_bus(layer="m2", - pitch=self.m2_pitch, - offset=input_offset, - names=input_bus_names, - length=self.height) + self.predecode_bus = self.create_vertical_pin_bus(layer="m2", + pitch=self.m2_pitch, + offset=vector(0, 0), + names=input_bus_names, + length=self.height) - self.route_rails_to_predecodes() - self.route_rails_to_decoder() - - def route_rails_to_predecodes(self): - """ Iterates through all of the predecodes and connects to the rails including the offsets """ + self.route_bus_to_predecodes() + self.route_bus_to_decoder() + def route_bus_to_predecodes(self): + """ + Iterates through all of the predecodes + and connects to the rails including the offsets + """ # FIXME: convert to connect_bus for pre_num in range(self.no_of_pre2x4): for i in range(4): predecode_name = "predecode_{}".format(pre_num * 4 + i) out_name = "out_{}".format(i) pin = self.pre2x4_inst[pre_num].get_pin(out_name) - self.route_predecode_rail_m3(predecode_name, pin) + x_offset = self.pre2x4_inst[pre_num].rx() + self.m2_pitch + self.route_predecode_bus_inputs(predecode_name, pin, x_offset) # FIXME: convert to connect_bus for pre_num in range(self.no_of_pre3x8): @@ -472,44 +494,68 @@ class hierarchical_decoder(design.design): predecode_name = "predecode_{}".format(pre_num * 8 + i + self.no_of_pre2x4 * 4) out_name = "out_{}".format(i) pin = self.pre3x8_inst[pre_num].get_pin(out_name) - self.route_predecode_rail_m3(predecode_name, pin) + x_offset = self.pre3x8_inst[pre_num].rx() + self.m2_pitch + self.route_predecode_bus_inputs(predecode_name, pin, x_offset) - def route_rails_to_decoder(self): - """ Use the self.predec_groups to determine the connections to the decoder AND gates. - Inputs of AND2/AND3 gates come from different groups. - For example for these groups [ [0,1,2,3] ,[4,5,6,7], - [8,9,10,11,12,13,14,15] ] the first AND3 inputs are connected to - [0,4,8] and second AND3 is connected to [0,4,9] ........... and the - 128th AND3 is connected to [3,7,15] + def route_bus_to_decoder(self): """ - row_index = 0 + Use the self.predec_groups to determine the connections to the decoder AND gates. + Inputs of AND2/AND3 gates come from different groups. + For example for these groups + [ [0,1,2,3] ,[4,5,6,7], [8,9,10,11,12,13,14,15] ] + the first AND3 inputs are connected to [0,4,8], + second AND3 is connected to [0,4,9], + ... + and the 128th AND3 is connected to [3,7,15] + """ + output_index = 0 + if (self.num_inputs == 4 or self.num_inputs == 5): for index_B in self.predec_groups[1]: for index_A in self.predec_groups[0]: # FIXME: convert to connect_bus? - if (row_index < self.num_outputs): + if (output_index < self.num_outputs): + row_index = math.floor(output_index / self.decoders_per_row) + row_remainder = (output_index % self.decoders_per_row) + row_offset = row_index * self.and_inst[0].height + (2 * row_remainder + 4) * self.m1_pitch predecode_name = "predecode_{}".format(index_A) - self.route_predecode_rail(predecode_name, self.and_inst[row_index].get_pin("A")) + self.route_predecode_bus_outputs(predecode_name, + self.and_inst[output_index].get_pin("A"), + row_offset) predecode_name = "predecode_{}".format(index_B) - self.route_predecode_rail(predecode_name, self.and_inst[row_index].get_pin("B")) - row_index = row_index + 1 + self.route_predecode_bus_outputs(predecode_name, + self.and_inst[output_index].get_pin("B"), + row_offset + self.m1_pitch) + output_index = output_index + 1 elif (self.num_inputs > 5): for index_C in self.predec_groups[2]: for index_B in self.predec_groups[1]: for index_A in self.predec_groups[0]: # FIXME: convert to connect_bus? - if (row_index < self.num_outputs): + if (output_index < self.num_outputs): + row_index = math.floor(output_index / self.decoders_per_row) + row_remainder = (output_index % self.decoders_per_row) + row_offset = row_index * self.and_inst[0].height + (3 * row_remainder + 4) * self.m1_pitch predecode_name = "predecode_{}".format(index_A) - self.route_predecode_rail(predecode_name, self.and_inst[row_index].get_pin("A")) + self.route_predecode_bus_outputs(predecode_name, + self.and_inst[output_index].get_pin("A"), + row_offset) predecode_name = "predecode_{}".format(index_B) - self.route_predecode_rail(predecode_name, self.and_inst[row_index].get_pin("B")) + self.route_predecode_bus_outputs(predecode_name, + self.and_inst[output_index].get_pin("B"), + row_offset + self.m1_pitch) predecode_name = "predecode_{}".format(index_C) - self.route_predecode_rail(predecode_name, self.and_inst[row_index].get_pin("C")) - row_index = row_index + 1 + self.route_predecode_bus_outputs(predecode_name, + self.and_inst[output_index].get_pin("C"), + row_offset + 2 * self.m1_pitch) + output_index = output_index + 1 def route_vdd_gnd(self): - """ Add a pin for each row of vdd/gnd which are must-connects next level up. """ + """ + Add a pin for each row of vdd/gnd which are + must-connects next level up. + """ # The vias will be placed in the center and right of the cells, respectively. xoffset = self.and_inst[0].rx() @@ -526,23 +572,42 @@ class hierarchical_decoder(design.design): self.copy_layout_pin(pre, "vdd") self.copy_layout_pin(pre, "gnd") - def route_predecode_rail(self, rail_name, pin): - """ Connect the routing rail to the given metal1 pin """ - rail_pos = vector(self.predecode_rails[rail_name].x, pin.lc().y) - self.add_path("m1", [rail_pos, pin.lc()]) - self.add_via_center(layers=self.m1_stack, - offset=rail_pos) + def route_predecode_bus_outputs(self, rail_name, pin, y_offset): + """ + Connect the routing rail to the given metal1 pin + using a routing track at the given y_offset + + """ + pin_pos = pin.center() + # If we have a single decoder per row, we can route on M1 + if self.decoders_per_row == 1: + rail_pos = vector(self.predecode_bus[rail_name].x, pin_pos.y) + self.add_path("m1", [rail_pos, pin_pos]) + self.add_via_center(layers=self.m1_stack, + offset=rail_pos) + # If not, we must route over the decoder cells on M3 + else: + rail_pos = vector(self.predecode_bus[rail_name].x, y_offset) + mid_pos = vector(pin_pos.x, rail_pos.y) + self.add_wire(self.m2_stack[::-1], [rail_pos, mid_pos, pin_pos]) + self.add_via_center(layers=self.m2_stack, + offset=rail_pos) + self.add_via_center(layers=self.m1_stack, + offset=pin_pos) - def route_predecode_rail_m3(self, rail_name, pin): - """ Connect the routing rail to the given metal1 pin """ + def route_predecode_bus_inputs(self, rail_name, pin, x_offset): + """ + Connect the routing rail to the given metal1 pin using a jog + to the right of the cell at the given x_offset. + """ # This routes the pin up to the rail, basically, to avoid conflicts. # It would be fixed with a channel router. - mid_point = vector(pin.cx(), pin.cy() + self.inv.height / 2) - rail_pos = vector(self.predecode_rails[rail_name].x, mid_point.y) + pin_pos = pin.center() + mid_point1 = vector(x_offset, pin_pos.y) + mid_point2 = vector(x_offset, pin_pos.y + self.inv.height / 2) + rail_pos = vector(self.predecode_bus[rail_name].x, mid_point2.y) + self.add_wire(self.m1_stack, [pin_pos, mid_point1, mid_point2, rail_pos]) self.add_via_center(layers=self.m1_stack, - offset=pin.center()) - self.add_wire(("m3", "via2", "m2"), [rail_pos, mid_point, pin.uc()]) - self.add_via_center(layers=self.m2_stack, offset=rail_pos) def input_load(self): diff --git a/compiler/pgates/pnand3.py b/compiler/pgates/pnand3.py index e7cc02e8..58894ccf 100644 --- a/compiler/pgates/pnand3.py +++ b/compiler/pgates/pnand3.py @@ -221,7 +221,7 @@ class pnand3(pgate.pgate): self.nmos3_inst, self.inputC_yoffset, "C", - position="center") + position="left") # FIXME: constant hack if OPTS.tech_name == "s8": @@ -232,7 +232,7 @@ class pnand3(pgate.pgate): self.nmos1_inst, self.inputA_yoffset, "A", - position="center") + position="left") def route_output(self): """ Route the Z output """ @@ -255,10 +255,10 @@ class pnand3(pgate.pgate): directions=("V", "V")) # PMOS3 and NMOS3 are drain aligned - self.add_path("m2", [pmos3_pin.center(), nmos3_pin.center()]) + self.add_path("m1", [pmos3_pin.center(), nmos3_pin.center()]) # Route in the A input track (top track) mid_offset = vector(nmos3_pin.center().x, self.inputA_yoffset) - self.add_path("m2", [pmos1_pin.center(), mid_offset, nmos3_pin.uc()]) + self.add_path("m1", [pmos1_pin.center(), mid_offset, nmos3_pin.uc()]) # This extends the output to the edge of the cell self.add_via_center(layers=self.m1_stack, diff --git a/compiler/tests/06_hierarchical_decoder_test.py b/compiler/tests/06_hierarchical_decoder_test.py index df979657..7b77c6d9 100755 --- a/compiler/tests/06_hierarchical_decoder_test.py +++ b/compiler/tests/06_hierarchical_decoder_test.py @@ -20,15 +20,6 @@ class hierarchical_decoder_test(openram_test): def runTest(self): config_file = "{}/tests/configs/config".format(os.getenv("OPENRAM_HOME")) globals.init_openram(config_file) - # Doesn't require hierarchical decoder - # debug.info(1, "Testing 4 row sample for hierarchical_decoder") - # a = hierarchical_decoder.hierarchical_decoder(name="hd1, num_outputs=4) - # self.local_check(a) - - # Doesn't require hierarchical decoder - # debug.info(1, "Testing 8 row sample for hierarchical_decoder") - # a = hierarchical_decoder.hierarchical_decoder(name="hd2", num_outputs=8) - # self.local_check(a) # check hierarchical decoder for single port debug.info(1, "Testing 16 row sample for hierarchical_decoder")