Abstract: A pair of communications adapters each include a number of digital signal processors and network interface circuits for the attachment of a multi-channel telephone line. A bus connecting the communications adapters can carry data between a network line attached to one of the adapters and the digital signal processors of the other adapter. The digital signal processors on each card are connected to a host, or controller, processor. Each digital signal processor interrupts its host processor by transmitting an interrupt control block as data to a data memory of the host processor, and by subsequently sending an interrupt causing the host processor to examine the data memory. Preferably, the interrupt control block includes data representing a number of requested interrupts.

Abstract: The processing speed of a digital signal processor or system processor is controlled in accordance with the functions required in a task to be performed by the device, with these functions being compared to a table of maximum processing speeds at which various functions can be performed reliably by the device. This method is applied to a number of digital signal processors on a communications adapter, with a core kernel of each of these digital signal processors being driven at a processing speed controlled in this way, while peripheral functions of all these digital signal processors are performed according to a clock signal synchronized with data being received from a network transmission line.

Abstract: A pair of communications adapters each include a number of digital signal processors and network interface circuits for the attachment of a multi-channel telephone line. A bus connecting the communications adapters can carry data between a network line attached to one of the adapters and the digital signal processors of the other adapter. The digital signal processors on each card are connected to a host, or controller, processor. Each digital signal processor interrupts its host processor by transmitting an interrupt control block as data to a data memory of the host processor, and by subsequently sending an interrupt causing the host processor to examine the data memory. Preferably, the interrupt control block includes data representing a number of requested interrupts.

Abstract: There is provided a Direct Access Memory Unit (DAu) that is associated with a remote processor module in a multi-processing system. The DAU performs Direct Memory Access (DMA) operations independently of a Central Processing Unit (CPU) in the remote processor module. The CPU requests a DMA by writing information relevant to the DMA to the remote processor's memory. The address of each control block is written to a circular queue, also in the remote processor's memory. The DAU determines if there are any control blocks to process and if so, the DAU will perform the DMA operation (reading data from or writing data to the memory of the host processor), all without the intervention of the CPU of the remote processor module. The CPU adds a new control block by loading its address in a location in the circular queue that is ahead of the circular queue location that the DAU is processing. The CPU can abort a pending DMA request during DAU operations by setting a skip bit in the control block.

Abstract: A multi-mode time division multiplexing (TDM) interface circuit for interfacing between a serial data port and a data buffer is provided. The TDM interface circuit contains a transmitter and a receiver section. The circuit is programmable to operate in a variety of modes and is capable of supporting various multi-channel TDM interfaces as well as single channel analog interfaces. The circuit is programmable by writing a control word to a control register. In operation the circuit receives a frame synchronization signal, a gated bit clock signal, and a bit clock signal from the circuit with which it is interfacing on the serial data port. A base address input to a base address register provides up to 9 of the most significant bits of a data buffer address. A 12-bit counter is used to generate the remaining (least significant) bits of the data buffer address according to the control word in the control register.

Abstract: A digital signal processing system includes first and second logical memory mapping units coupled to first and second digital processors respectively and to a data storage unit. The system further includes first and second mapping registers for containing first and second address mapping information coupled to the first and second digital processors respectively. The first and second mapping units are operative to receive (i) first and second logical addresses generated by the first and second digital processors respectively and (ii) first and second address mapping information respectively, and generate first and second physical addresses such that each of the digital processors can independently access any of a plurality of memory locations within the data storage unit.

Abstract: An interprocessor interrupt hardware unit ("IIU") for processing interrupts between a remote processor and a host processor on a multiprocessor system. The IIU off loads tasks involved in processing interrupts from the operating kernel of the remote processor. Control blocks of interrupt information and commands are stored in Data Random Access Memory (DRAM) by the remote processor. The remote processor sets up a buffer of control block memory addresses in DRAM for the IIU to access to retrieve the control blocks from DRAM. The IIU retrieves a control block and loads the control block into registers. The IIU then issues an interrupt request to the host processor. The host processor receives the interrupt request and reads the registers to obtain the control block. The host processor clears the interrupt request and indicates to the IIU that the interrupt has been processed. The IIU then notifies the remote processor that the interrupt has been processed.

Abstract: This I/O interface permits attachment of a data processing system to devices having different "handshaking" protocols and bit-parallel data exchange capacities. Handshaking control circuits permit the system to communicate with devices variously in pulsed and interlocked modes. Timer circuits provide a variety of different time reference signals for transfer to devices. Switching options associated with the timer permit selective use of timer outputs as pulsed mode handshaking functions. A counter circuit and associated interface port permit the system to count events associated with device-originated pulses. A switching option permits the counter incrementing operations to be governed by timer outputs. The interface also contains path selection lines. In one mode these lines define high speed exchange of data between a primary system processor and devices in various bit-parallel formats and over various buses designatable by a systems processor.