Abstract: The present invention provides digital integrated circuits, buffers, digital devices and methods for buffering data. One embodiment of the digital integrated circuit comprises: a data input configured to receive an input signal at a first voltage; a data output configured to output an output signal at a second voltage; a controller coupled with the data input and the controller being configured to generate an internal control signal and an external control signal responsive to the input signal; the controller having a first voltage regulator configured to maintain the external control signal above a threshold and a feedback voltage regulator configured to maintain the internal control signal above a threshold; and an output driver coupled with the data output and the controller, the output driver being configured to apply the output signal to the data output responsive to the external control signal.

Abstract: An I/O buffer is provided that is noise-isolated, i.e., less susceptible to the effect of switching noise. In particular, a noise isolated I/O buffer includes an output terminal, a transient switching circuit connected to first power and ground voltage sources, to a logic input signal and to the output terminal, and a logic holding circuit connected to second power and ground voltage sources separate from the first power ground voltage sources, to the logic input signal and to the output terminal. The transient switching circuit causes a logic level of the output terminal to be switched responsive to a change in the input signal. The logic holding circuit causes the logic level of the output terminal to be maintained in the absence of a change in the input signal. In the absence of a change in the input signal, the transient switching circuit may be turned off, therefore presenting a high impedance to the first power and ground voltage sources.

Abstract: An I/O buffer is provided that is noise-isolated, i.e., less susceptible to the effect of switching noise. In particular, a noise isolated I/O buffer includes an output terminal, a transient switching circuit connected to first power and ground voltage sources, to a logic input signal and to the output terminal, and a logic holding circuit connected to second power and ground voltage sources separate from the first power ground voltage sources, to the logic input signal and to the output terminal. The transient switching circuit causes a logic level of the output terminal to be switched responsive to a change in the input signal. The logic holding circuit causes the logic level of the output terminal to be maintained in the absence of a change in the input signal. In the absence of a change in the input signal, the transient switching circuit may be turned off, therefore presenting a high impedance to the first power and ground voltage sources.

Abstract: A transparent power grid is formed using a first metal layer and a second metal layer in a gate array having defined therein well tie-down regions. The first metal layer includes first power supply busses for supplying operating and reference voltages to the transistors, the first power supply busses extending in a row direction and overlapping the well tie-down region. The second metal layer includes second power supply busses for supplying operating and reference voltages to the transistors, the second power supply busses extending in a column direction and overlapping the well tie-down regions and the first power supply busses. Vias are formed where first and second power supply busses each supplying a same one of the operating voltage and the reference voltage overlap, thereby connecting the first and second power supply busses.

Abstract: Flexible routing of gate arrays increases routing efficiency, provides for the routing of functional blocks with other gates in the gate array, and provides structures for flexible power routing, particularly of gate arrays having functional blocks. In particular, a gate-array-implemented integrated circuit is designed using a computer by representing in computer memory a gate array base, placing gate array cells on the gate array base in placement rows each having a uniform height and separated by routing channels in which no gate array cells are placed, and routing in the routing channel connections between placement rows according to a netlist, during routing increasing the size of a routing channel if required and decreasing the size of a routing channel if possible by changing the placement of at least one placement row by an amount less than half the height of the placement row. Routing channel size is therefore flexibly adjusted "on-the-fly" during routing, increasing routing efficiency.

Abstract: When a user requests a RAM or other semiconductor memory to be compiled with a number of rows that is not a power of two, the compiler creates the RAM with one extra row. The rows requested by the user are placed at contiguous row addresses starting at zero and ending at one less than the number of rows requested. The highest of these row addresses is placed permanently in a comparator by the compiler. The comparator then compares each row address input to the RAM to the row address contained in the comparator. If the row address input is higher, then the comparator selects the extra row. The extra row can be written into or read from in the same manner as any other row in the RAM. The delay of the comparator is comparable to the delay of the address decoder, so that the RAM operates within the same specifications regardless of whether the address decoder selects a row or the comparator selects the extra row.