Semiconductor device having a reduced footprint of wires connecting a DLL circuit with an input/output buffer
An apparatus includes a clock terminal configured to receive an external clock signal, a clock generator configured to generate an internal clock signal in response to the external clock signal, first and second output circuits each coupled to the clock generator, a first clock line coupled between the clock generator and the first output circuit, and the second clock line coupled between the clock generator and the second output circuit. The first clock line represents a first capacitance and a first resistance while the second clock line represents a second capacitance and a second resistance. A first value defined as the product of the first capacitance and the first resistance is substantially equal to a second value defined as the product of the second capacitance and the second resistance.
1. An apparatus comprising:
a clock buffer circuit configured to provide an internal clock signal;
a first group of output circuits, wherein each of the output circuits of the first group are coupled to the dock buffer circuit with a resistor element therebetween and configured to operate in response to the internal clock signal, wherein the resistor element includes a first wiring layer and the resistor element is coupled to the first output circuit through a second wiring layer different than the first wiring layer; and
a second group of output circuits, wherein each of the output circuits of the second group are coupled to the clock buffer circuit without any resistor elements therebetween and configured to operate in response to the internal clock signal.
2. The apparatus as claimed in claim 1 , wherein the first group of output circuits is closer to the clock buffer circuit than the second group of output circuits.
3. The apparatus as claimed in claim 1 , wherein the first wiring layer includes a tungsten wiring layer.
4. The apparatus as claimed in claim 1 , wherein each output circuit of the first group and the second group of output circuits are configured to receive respective data and output the respective data in response to the internal clock.
5. The apparatus as claimed in claim 1 , further comprising data output terminals coupled to each output circuit of the first and second groups of output circuits.
6. The apparatus as claimed in claim 1 , further comprising:
a plurality of first clock paths, each of the plurality of first clock paths including the resistor element and configured to transfer the internal clock signal from the clock buffer circuit to a respective output circuit of the first group of output circuits; and
a plurality of second clock paths, each of the plurality of second cloth paths configured to transfer the internal clock signal from the clock buffer circuit to a respective output circuit of the the second group of output circuits, and
wherein the plurality of first clock paths is less in length than plurality of second clock paths.
7. The apparatus as claimed in claim 1 , wherein the first and second groups of output circuits are configured to operate in substantially parallel to each other.
8. The apparatus of claim 1 , wherein the output circuits of the first group are adjacent to one another, and wherein the output circuits of the second group are adjacent to one another.
9. An apparatus comprising:
a clock buffer circuit configured to provide an internal clock signal;
a clock trunk line coupled to the clock buffer circuit to convey the internal signal and elongated in line;
first and second groups of output circuits configured to operate in response to the internal clock signal, each output circuit of the first and second groups being arranged in line along the clock trunk line such that the output circuits of the first group are closer to the clock buffer circuit than the output circuits of the second group;
a plurality of first clock lines each connecting the clock trunk line to one of the output circuits of the first group, the first clock lines each including a first resistor element; and
a plurality of second clock lines each connecting the clock trunk line to one of the output circuits of the second group, wherein each of the second clock lines are without any resistor elements, and wherein the plurality of second clock lines are greater in length than the plurality of first clock lines.
10. The apparatus as claimed in claim 9 , wherein the first resistor element includes a wiring layer.
11. The apparatus as claimed in claim 10 , wherein the wiring layer includes a tungsten wiring layer.
12. The apparatus as claimed in claim 9 , further comprising output terminals coupled to each of the output circuits of the first and second groups of output circuits.
13. The apparatus as claimed in claim 9 , further comprising a multi-level wiring structure including a first wiring layer, a second wiring layer formed over the first wiring layer and a third wiring layer formed over the second wiring layer, and wherein each of the plurality of first clock lines is formed from the first wiring layer, the second wiring layer and the third wiring layer, and each of the plurality of second clock lines is formed from the second wring layer and the third wiring layer and without the first wiring layer.
14. An apparatus comprising:
a first wiring layer including a first conductive material;
a second wiring layer including a second conductive material that is lower in resistivity than the first material;
a buffer circuit configured to provide an internal timing signal;
first and second groups of output circuits configured to operate in response to the internal timing signal, the first and second groups of output circuits being arranged such that the first group of output circuits is closer to the buffer circuit than the second group of output circuits;
a plurality of first signal paths, each of the plurality of first signal paths connecting the buffer circuit to one of the output circuits of the first group, each of the plurality of first signal paths including the first wiring layer and the second wiring layer; and
a plurality of second signal paths, each of the plurality of second signal paths connecting the buffer circuit to one of the output circuits of the second group, each of the plurality of second signal paths including the second wiring layer and excluding the first wiring layer.
15. The apparatus as claimed in claim 14 , wherein the first conductive material includes tungsten and the second conductive material includes at least one of aluminum and copper.
16. The apparatus as claimed in claim 14 , wherein the second wiring layer is formed over the first wiring layer.
17. The apparatus as claimed in claim 14 , further comprising output terminals coupled to each of the output circuits of the first and second groups of output circuits.
18. The apparatus as claimed in claim 14 , wherein the internal timing signal includes an internal clock signal.