Abstract:
A microprocessor, including a synchronous type memory having several parts, includes a power saving feature that places at least some parts of the memory in a non-operating state when instructions not requiring access to the memory are executed. An enable signal is generated when access is not required and a signal supplying circuit supplies a synchronous signal when the enable signal is not generated and supplies a signal in a predetermined state to place at least some parts or all parts of the memory in the non-operating state to reduce power consumption.
Abstract:
The operation speed of a full adder is increased by avoiding the necessity of forming the inverse signal for adder operation and deleting the time required for passing through an inverter.
Abstract:
Decrease in throughput performance called a “jamming” in a memory device is prevented. There is provided a timing generation part which gives, based on a request signal outputted for each unit of the data processing from a data processing part, an output timing for a burst transfer request to a burst transfer request generation part. Based on the relationship in size between a lapsed time from the output of the burst transfer request to the activation of the request signal and a time specified by a set threshold value of a threshold value register, the timing generation part controls output timing for a burst transfer request. When the lapsed time exceeds the time specified by a maximum threshold value, the burst transfer request generation part is given an output timing for the burst transfer request without waiting for the activation of the request signal. As a result, when the issuance of the request signal is delayed, a next burst transfer request can be given to the memory device without waiting for the issuance but preceding it.
Abstract:
When a line number counted by a line number counting unit corresponds to a prescribed line number, a transfer source address generating unit adds an offset address set in an offset address setting unit to respective transfer source addresses to output as addresses to a memory. A DMA control unit controls DMA transfer in accordance with a transfer source address generated by the transfer source address generating unit and a transfer destination address generated by a transfer destination address generating unit. Thus, rapid enlargement/reduction of image data becomes possible.
Abstract:
When a line number counted by a line number counting unit corresponds to a prescribed line number, a transfer source address generating unit adds an offset address set in an offset address setting unit to respective transfer source addresses to output as addresses to a memory. A DMA control unit controls DMA transfer in accordance with a transfer source address generated by the transfer source address generating unit and a transfer destination address generated by a transfer destination address generating unit. Thus, rapid enlargement/reduction of image data becomes possible.
Abstract:
An operation circuit for performing either fixed or floating point mathematical operations, having a mode control function for a multiplier including a multiplier, an arithmetic logic unit (ALU) and a signal generating circuit. A signal specifying the operating mode of the ALU, either a fixed point mode or a floating point mode is used by the signal generating circuit for generating either a fixed point multiplication signal or a floating point multiplication signal to control the multiplier, respectively.
Abstract:
A decimation type digital filter which utilizes the thinned-out signal of a finite impulse response (FIR) filter having N taps for processing the signal by the product sum operation of filter coefficients and the input signals inputted at every first period, in which, on the basis of the ratio K between a first period which is the input signal period and an output signal period and the number of taps N, M (a value obtained by raising below the decimal point of N/K) registers are provided and M successive output signals are processed by the product sum operation in parallel by respective registers, whereby the input signal is not necessarily to be held, a capacity of the register may be minimized and processing may be effected once for each register during the first period or by M number of times of product sum operation in total, thus the operating speed can be reduced to 1/K and the capacity and the operating speed can be optimized.
Abstract:
When a line number counted by a line number counting unit corresponds to a prescribed line number, a transfer source address generating unit adds an offset address set in an offset address setting unit to respective transfer source addresses to output as addresses to a memory. A DMA control unit controls DMA transfer in accordance with a transfer source address generated by the transfer source address generating unit and a transfer destination address generated by a transfer destination address generating unit. Thus, rapid enlargement/reduction of image data becomes possible.
Abstract:
A 3-bit condition execution field in an condition execution instruction stores an encoded value obtained by encoding a condition stored in an general purpose flag indicating to execute the condition execution instruction. A microprocessor has an instruction decode unit 2 comprising a condition execution decode section 401 for decoding a value in the condition execution field and a condition execution judgement section 402 for judging whether or not the decoded result from the condition execution decode section 401 is equal to a condition stored in general purpose flags, and outputting the indication to execute the condition execution instruction when both are equal.
Abstract:
An A/D-D/A converting apparatus, in which a multiplier is omitted by storing the multiplied result of a filter coefficient and a digital signal in advance and reading it out responsive to the inputted digital signal, in view of the point that filter characteristics of digital filters of an A/D converting unit and a D/A converting unit are equal one another, memories which are coefficient generating devices are used in common, and further, in view of the point :hat processing contents of respective digital filters are equal, a multiplier and an accumulator constituting the digital filter are used in common to reduce a circuit configuration considerably.