Abstract: A finite impulse response filter (90) has a data memory bank (92, 350) for storing data vectors and a coefficient memory bank (91, 300) for storing coefficient vectors. Filtering is done by multiplying data words by coefficient words, and summing the results. The finite impulse response filter (90) operates in different modes, according to the type of data vector and coefficient vector. In two modes of operation consecutive elements of the data vector (360-369, 460-475) are stored in consecutive odd memory words (380, 382..396) within the data memory bank (92, 350). In other modes consecutive elements of the data vector are stored in consecutive memory words (380-397) in the data memory bank (92, 350). Consecutive coefficient vector elements (310-319, 410-419) are stored in the consecutive memory words (340-349) in coefficient memory bank (91, 300), wherein coefficient elements can be stored in reverse or forward order.

Abstract: The present invention relates to memory and methods for storing/retrieving data in/from the memory that is accessed by at least two distinct data uses of different actual word widths. A memory for storing addressable binary data comprises a data storage organized in rows and columns of bit array cells, row address decoder and driver for addressing a selected row of bit array cells, column drivers for driving selected columns of bit array cells, and a bus switch port for selectively transferring data between the data storage and a first data bus with a first bus word width p and a second data bus with a second bus word width q smaller than the first bus word width p.

Abstract: According to the present invention, an LFSR (300) has a propagation path (30) of serially coupled stages (65) and gates (80-3, 80-4), a feedforward path (10) of gates (80-1) and a feedback path (20) of gates (80-2). Depending on control signals (P, B, M), the gates (80-1, 80-2, 80-3, 80-4) are either active gates and operate as xor-gates or passive gates and operate as transfer gates. Feedforward and feedback signals are derived from input and output signals and can be supplied to any stage (65), so that characteristic polynomials of the input-output function are variable. The LFSR can fully or partly operate as a TYPE 1 or TYPE 2 LFSR which enables the execution of different algorithms on one hardware base.

Abstract: The present invention relates to multi-bit exclusive-or (XOR) gates (60), including those where N parallel input bits (36, 38) are XORed with one data input bit (52). A modular approach is made using only one basic cell (30) for various implementations with different propagation delays. An N-bit XOR comprises basic cells (30) of adjacent first and second XOR gates (32, 34). Each first XOR gate (32) processes as input two of said N primary input bits (36, 38) and each second XOR gate (34) processes as input bits output bits of first or second XOR gates (32, 34) or the input data bit (52). This structure makes it possible to create an array of identical basic cells which is very suitable for VLSI implementation. There are few lines of connections between the different cells in the cell array which leads to substantial reduction in propagation delay without adding substantial wiring or layout complexity.

Abstract: A filter co-processor within a Digital Signal Processor (DSP) takes advantage of the orthogonal nature of modulated signals during the equalization process. Since, after reception, only certain real/imaginary values of the received signal are useful for demodulation, the filter co-processor only processes those values to estimate the transmitted signal. By processing only those values useful for demodulation, the filter co-processor is able to process more information in a given amount of time, leading to increased processing when compared to the prior art.

Abstract: A method for ensuring CRC error generation by a data communication station after a transmitter exception such as an underrun whereby a parity bit is preset to a binary one, and toggled in response to successive binary ones of a serial bit stream. Each byte of the serial bit stream is transmitted sequentially. If a transmitter exception occurs, the byte before the exception is transmitted normally. However, only the first seven bits of the last byte are transmitted. The parity bit is sent as an eighth bit of the last byte, ensuring odd parity for the previous bit stream. Thereafter, a byte even parity is sent to assure that the overall message has odd parity. A receiving station interprets two consecutive bytes having the predetermined data pattern as the CRC, thus ensuring that the receiving station will reject the frame.