Abstract:
Systems and methods are provided for writing code to access data arrays. One aspect provides a method of accessing a memory array. Data is provided within a one-dimensional array of allocated memory. A dimensional dynamic overlay is declared from within a block of statements, and the declaration initializes various attributes within an array attribute storage object. The data is accessed from within the block of statements as a dimensional indexed array using the array attribute storage object. Another aspect provides a method of creating and accessing a dimensional dynamic array. A dimensional dynamic array is declared from within a block of statements, and memory storage for the array is dynamically allocated. A dynamic overlay storage object is also provided and its attributes are initialized from the dynamic array declaration. The data is accessed as a dimensional indexed array from within the block of statements using the array attribute storage object.
Abstract:
Systems and methods are provided for caching dynamic arrays. According to one aspect, a cache memory device is provided for caching dynamic arrays or dynamic overlays. According to one embodiment, the device includes a plurality of memory cells and at least one register for storing access information to access at least one array stored in the plurality of memory cells. According to another aspect, an electronic system is provided that includes a main memory, a dynamic array cache memory device, a general cache memory device, and a processor. The dynamic array cache memory device is coupled to the main memory and adapted for caching array data. The general cache memory device is coupled to the main memory and is adapted for caching regular data. The processor is coupled to and adapted for communication with the main memory, the general cache memory device, and the dynamic array cache memory device.
Abstract:
A calibration system for calibrating a linearity corrector using the sum of filter products is proved, along with a method of calibrating the linearity corrector. The calibration system includes a first and second signal generator for introducing test signals into a signal processing system, such as an ADC. An acquisition memory and processor are provided for acquiring and analyzing the output of the signal processing system and then programming the filter coefficients into the linearity corrector. The method of calibration analyzes acquired intermodulation and harmonic components from the signal processing system and then finds the amplitude and phase response for the filters. The amplitude and phase response is then used to determine a set of filter coefficients.
Abstract:
A method and system for calculating resample output values from input samples and their associated sample values. A resampling circuit calculates a frequency value for a sine-wave model from a sample set of the input samples and determines whether the frequency value is in a frequency range. In the case where the frequency value is in the frequency range, a sinusoidal transition model is determined based on the sample set. However, if the frequency value is outside of the frequency range, a non-sinusoidal model is determined based on the sample set. The resampling circuit then calculates resample output values from the resulting sinusoidal or non-sinusoidal model.
Abstract:
A method and system for calculating resample output values from input samples and their associated sample values. A resampling circuit calculates a frequency value for a sine-wave model from a sample set of the input samples and determines whether the frequency value is in a frequency range. In the case where the frequency value is in the frequency range, a sinusoidal transition model is determined based on the sample set. However, if the frequency value is outside of the frequency range, a non-sinusoidal model is determined based on the sample set. The resampling circuit then calculates resample output values from the resulting sinusoidal or non-sinusoidal model.
Abstract:
An economical method of detecting and suppressing ringing artifacts during digital image resizing is presented. The economical method substitutes costly division calculations with cost effective comparator operations. The method also includes improved image sharpening when up-sampling an image.
Abstract:
Asymmetric finite impulse response (FIR) filters are used to estimate gradients for re-sampling models used in image resizing. Better than conventional 3-tap symmetric FIR filters, these filters provide good edge and extended-frequency responses with good narrow peak sharpening characteristics. These filters emphasize accurate edge handling, where gradients are steepest, over accurate peak handling, where gradients are shallowest. This results in superior zone-plate test signals and better resized image quality.
Abstract:
An improved FIR filter based upon squaring is used to self-determine a filter constant equal to the sum-of-squares of the filter coefficients. An input signal is forced to zero for T samples, where T is the number of accumulator cells in an accumulator stage, and at the end of such zero samples the output from the filter is latched as the filter constant for use in filtering the normal input signal. The FIR filter may also be placed in a co-processor mode, using a FIFO register between the input of the FIR filter and a processor bus. A CPU on the bus initiates the co-processor mode and loads data into the FIFO. When the FIFO has data the data is read out and input to the FIR filter. The output of the FIR filter is placed on the processor bus. To determine the values of the filter coefficients loaded in the FIR filter, the data loaded by the CPU is an impulse signal having T−1 zero samples before and after an impulse sample, the output for each sample representing one of the filter coefficients.
Abstract:
A method of encoded communication in which a receiver generates a receiver public key by looking up a monitoring authority public key, multiplying four prime numbers, and encoding the identities of two of the prime numbers with the monitoring authority public key. The receiver communicates the public key to a sender, who creates a message, encodes it with the receiver public key, and transmits it to the receiver. The receiver then decodes the encoded message with the four prime numbers. The monitoring authority may decode the two prime numbers of the receiver's key, and factorize the product of the remaining primes. An unauthorized party would be faced with the much more difficult or impossible task of factorizing the original product of the four primes.
Abstract:
Touch controlled zoom of a waveform display uses a touch screen for the display surface. Function buttons for moving or expanding the waveform display and for determining the axis of such movement or expansion operate in conjunction with a rotary encoder. Expansion, or zoom, is accomplished by contacting the screen overlying a point on the waveform about which zoom is desired. Such contact or activation of the expand function button results in movement of the rotary encoder providing a gain parameter to a zoom function. The zoom function operates on the waveform display in an exponential manner as a function of the gain parameter to expand or contract the waveform display about the zoom point according to the direction of rotation of the rotary encoder.