Abstract: A circuit for receiving multiple serial datastreams in parallel is disclosed. A bit clock is recovered from each data stream, there being one data bit for each transition of the clock signal both positive and negative going. The phases of the bit clocks are compared and are adjusted by 180 degrees so that the positive going edges of all occur close to each other. The bits of each stream are assembled into words under the control of a word clock. In one embodiment a common word clock is derived form the set of bit clocks as a whole. In another embodiment each stream is provided with its own word clock which is aligned to positive edges of the respective bit clocks that are close to each other.

Abstract: An asynchronous time division multiplex switching arrangement comprises a serial to parallel converter arranged to receive input packets of data which include routing information, in serial form and convert the packets of data to parallel form. A random access memory is provided in which each packet of data is entered at an addressed location into the memory, and the address is entered in a respective first-in first-out output queue at the tail. The address at the head of the queue is accessed and the packet of data is read from the random access memory into a parallel to serial converter and the packet of data is serially delivered to the associated output.

Abstract: A power supply for an integrated circuit chip, including supply regulation circuitry coupled between on-chip circuitry and a power supply connection, the supply regulation circuitry including a transistor having a diode coupled to the control electrode of the transistor, the diode having a relatively large diode junction area, and a resistor coupled in series with the main current path of the transistor having a relatively small or no diode junction area, whereby when the chip is subject to irradiation the diode means increases the conductivity of the main current path so that an increased voltage appears across the resistor thereby to reduce the supply voltage to the on-chip circuitry.