O) will open a checkbox window that you can use to open the standard palettes in all of the installed domains. For the CG56 domain, the star library is large enough that it has been divided into sub-palettes as was done with the SDF main palette.
The top-level palette is shown in figure 15-1. The palettes are Signal Sources, I/O, Arithmetic, Nonlinear Functions, Logic, Control, Conversion, Signal Processing, and Higher Order Functions. The stars on the Higher Order Functions (HOF) palette are used to help lay out schematics graphically. The HOF stars are in the HOF domain, and not the CG56 domain. The names of the others palettes are modeled after the SDF star palettes of the same name in section 5.2 on page 5-4, except the I/O palette which contains target-specific I/O stars for the Ariel S-56X DSP board and the Motorola 56001 simulator. Each palette is summarized in more detail below. More information about each star can be obtained using the on-line "profile" command (
,), the on-line man command (
M), or by looking in the Star Atlas volume of The Almagest.
At the top of each palette, for convenience, are instances of the delay icon, the bus icon, and the following star:
BlackHoleDiscard all inputs. This star is useful for discarding signals that are not useful.
ImpulseGenerate a single impulse of size impulseSize (default
IIDGaussianGenerate a white Gaussian pseudo-random process with mean 0 and standard deviation 0.1. A Gaussian distribution is realized by summing noUniforms (default 16) number of uniform random variables. According to the central limit theorem, the sum of N random variables approaches a Gaussian distribution as N approaches infinity.
IIDUniformGenerate an i.i.d. uniformly distributed pseudo-random process. Output is uniformly distributed between -range and range (default
ToneGenerate a sine or cosine wave using a second order oscillator. The wave will be of amplitude (default 0.5), frequency (default 0.2), and calcType (default "sin")
Motorola 56000 Simulator I/O Stars
The palette of I/O stars for the Motorola 56K simulator target is shown in figure
ReadFileRead fixed-point ASCII data from a file. The simulation can be halted on end-of-file, or the file contents can be periodically repeated, or the file contents can be padded with zeros.
IntReadFileRead integer ASCII data from a file. The simulation can be halted on end-of-file, or the file contents can be periodically repeated, or the file contents can be padded with zeros.
WriteFileWrite data to a file. The simulator dumps the data presented at the input of this star into a specified file.
XgraphThis star shares the same parameters as its SDF and CGC star equivalents. However, with this star, you can only have one input signal. See "pxgraph - The Plotting Program" on page 20-1 to learn about plotting options.
adjustableGainGXCreate an interactive adjustable gain using HostSliderGX.
daSend the input to both input ports of the SSI star.
HostAOutOutput data from the DSP to host via host port asynchronously.
HostSldrGXGenerate an athena widget slider for interactive asynchronous input over the host port.
MagnavoxInRead data from a Magnavox CD player.
MagnavoxRead data from and write data to a Magnavox CD player.
MagnavoxOutWrite data to a Magnavox CD player.
PrPrtADRead from the A/D in Ariel ProPort.
PrPrtADDARead from the A/D and write to the D/A on the Ariel ProPort.To use both the A/D and D/A on a ProPort you must use this star and not the separate A/D and D/A stars.
PrPrtDAWrite to the D/A on the Ariel ProPort.
SSIA generic input/output star for the DSP56001 SSI port.
SSISkewInterface to the 56001 SSI's port with timing-skew capability.
HostButton(2 icons) Graphical two-valued input source. There are two types of buttons: push-buttons and check-buttons. Both present a single button to the user that may be "pressed" with the mouse. The buttons differ in the semantics of the push. When the pushbutton is pressed, the onVal state is output, otherwise offVal.
HostMButtonGraphical one-of-many input source. The star always outputs one of a finite number of values: the output is controlled by the user selecting one of several buttons. Exactly one button in the group is on.
HostSldrGraphical host slider for asynchronous input source.
SwitchDelayThis galaxy synchronously switches between the input value and the value of the input delayed by TotalDelay (default 8000) samples.
adjustableGainA user adjustable gain, uses
checkButtonIntThis galaxy creates a Tk checkbutton widget that produces the given onValue
(default 1) when pressed andoffValue (default 0) otherwise.
checkButtonThis galaxy creates a Tk checkbutton widget that produces the given onValue (default 1.0) when pressed and offValue (default 0.0) otherwise.
radioButtonInt This galaxy creates a Tk radiobutton widget that allows the user to select from among a set of possible output values given by pairs (default "One 1" "Two 2").
radioButtonThis galaxy creates a Tk radiobutton widget that allows the user to select from among a set of possible output values given by pairs (default "One 1" "Two 2")
sliderThis galaxy creates a Tk slider widget that produces the given value indicated by the slider position which is between low (default 0.0) and high (default 1.0) and initially set to value (default 0.0).
adjustableGainThis galaxy multiplies the input by a gain value taken from a Tk slider position between low (default 0.0) and high (default 1.0), which is initially set to value (default 0.0).
SwitchDelayThis galaxy synchronously switches between the input value and the value of the input delayed by TotalDelay (default 8000) samples.
s56XPlotThis galaxy plots the input interactively using TkPlot.
XgraphThis galaxy simply contains a
CGCXgraphstar for use in a CG56 galaxy. The galaxy parameters are identical to those of the enclosed star.
PeekPokeNondeterminate communication link that splices in a peek/poke pair. In this context, it provides a link between the S-56X Motorola 56001 board and the workstation.
Add(2 icons) Output the sum of the inputs. If saturation is set to yes, the output will saturate.
SubOutputs the "pos" input minus all of the "neg" inputs.
Mpy(2 icons) Outputs the product of all of the inputs.
GainThe output is set the input multiplied by a gain term. The gain must be in [-1,1).
AddCx(2 icons) Output the complex sum of the inputs. If saturation is set to yes, the output will saturate.
SubCxOutputs the "pos" input minus all of the "neg" inputs.
MpyCx(2 icons) Outputs the product of all of the inputs.
AddInt(2 icons) Output the sum of the inputs. If saturation is set to yes, the output will saturate.
SubIntOutputs the "pos" input minus all of the "neg" inputs.
MpyInt(2 icons) Outputs the product of all of the inputs.
GainIntThe output is set the input multiplied by an integer gain term.
DivByIntThis is an amplifier. The integer output is the integer input divided by the integer divisor (default 2). Truncated integer division is used.
MpyRxMultiply any number of rectangular complex inputs, producing an output.
MpyShiftMultiply and shift.
NegOutput the negation of the input.
ShifterScale by shifting left leftShifts bits. Negative values of leftShifts implies right shifting.
AbsOutput the absolute value of the input.
ACosOutput the inverse cosine of the input, which is in the range -1.0 to 1.0. The output, in the principle range of 0 to , is scaled down by .
ASinOutput the inverse sine of the input, which is in the range -1.0 to 1.0. The output, in the principle range of
CosOutput the cosine, calculated the table lookup. The input range is [-1,1] scaled by .
Output the complex exponential of the input.
IntgrtrAn integrator with leakage set by feedbackGain. If there is an overflow, the onOverflow parameter will designate a wrap around, saturate or reset operation.
LimitLimits the input between the range of [bottom, top].
LogOutputs the base two logarithm.
MaxMinOutput the maximal or minimal (MAX) sample out of the last N input samples. This can either compareMagnitude or take into account the sign. If outputMagnitude is
YESthe magnitude of the result is written to the output, otherwise the result itself is written.
ModuloIntOutput the remainder after dividing the integer input by the integer modulo parameter.
OrderTwoIntTakes two inputs and outputs the greater and lesser of the two integers.
QuantQuantizes the input to one of N+1 possible output levels using N thresholds.
QuantIdxThe star quantizes the input to one of N+1 possible output levels using N thresholds. It also outputs the index of the quantization level used.
QuantRangeQuantizes the input to one of N+1 possible output levels using N thresholds.
ReciprocalOutputs the reciprocal to Nf precision in terms of a fraction and some left shifts.
SgnOutputs the sign of the input.
SgnIntOutputs the sign of the integer input.
SinOutputs the sine, calculated using a table lookup. The input range is [-1,1) scaled by .
SincOutputs the sinc functions calculated as sin(x)/x.
SqrtOutputs the square root of the input.
TableImplements a real-valued lookup table. The values state contains the values to output; its first element is element zero. An error occurs if an out of bounds value is received.
TableIntImplements an integer-valued lookup table. The values state contains the values to output; its first element is element zero. An error occurs if an out of bounds value is received.
ExprGeneral expression evaluation.
LookupTblThe input accesses a lookup table. The interpolation parameter determines the output for input values between table-entry points. If interpolation is "linear" the star will interpolate between table entries; if interpolation is set to "none", it will use the next lowest entry.
PulseGenerates a variable length pulse. A pulse begins when a non-zero trigger is received. The pulse duration varies between 1 and maxDuration as the control varies between [-1,1).
QntBtsIntOutputs the two's complement number given by the top noBits of the input (for integer output).
QntBtsLinOutputs the two's complement number given by the top noBits of the input, but an optional offset can be added to shift the output levels up or down.
SkewGeneric skewing star.
SqrOutputs the square of the input.
VarQuasarA sequence of values(data) is repeated at the output with period N (integer input), zero-padding or truncating the sequence to N if necessary. A value of O for N yields an aperiodic sequence.
XorOutput the bit-wise exclusive-or of the inputs.
Test(4 icons) Test to see if two inputs are equal, not equal, greater than, and greater than or equal. For less than and less than or equal, switch the order of the inputs.
And(3 icons) True if all inputs are non-zero.
Nand(2 icons) True if all inputs are not non-zero.
Or(2 icons) True if any input is non-zero.
Nor(2 icons) True if any input is zero.
Xor(2 icons) True if an odd number of inputs is non-zero.
Xnor(2 icons) True if an even number of inputs is not non-zero.
Repeat, Reverse, and
ChopVarOffsetThis star has the same functionality as the
Chopstar except now the offset parameter is determined at run time through a control input.
CutOn each execution, this star reads a block of nread samples (default 128) and writes nwrite of these samples (default 64), skipping the first offset samples (default 0). It is an error if nwrite + offset > nread. If nwrite > nread, then the output consists of overlapping windows, and hence offset must be negative.
DelayA delay star of parameter totalDelay unit delays.
PadOn each execution, Pad reads a block of nread samples and writes a block of nwrite samples. The first offset samples have value fill, the next nread output samples have values taken from the inputs, and the last nwrite - nread - offset samples have value fill again.
RotateThe star reads in an input block of a certain length and performs a circular shift of the input. If the rotation is positive, the input is shifted to the left so that ouput = input[rotation]. If the rotation is negative, the input is shifted to the right so that output[rotation] = input.
sampleNholdGalaxyThis sample-and-hold galaxy is more memory efficient than using a downsample star for the same purpose.
VarDelayA variable delay that will vary between 0 and maxDelay as the control input varies between -1.0 and 1.0.
WasteCyclesStalls the flow of data for cyclesToWaste number of cycles.
CxToRectOutput the real part and imaginary part of the input of separate output ports.
RectToCxOutput a complex signal with real and imaginary part inputs.
BitsToIntConvert a stream of bits to an integer.
IntToBitsConvert an integer into a stream of bits.
FixToCxConvert fixed-point numbers to complex fixed-point numbers.
FixToIntConvert fixed-point numbers to complex fixed-point numbers.
CxToFixConvert fixed-point numbers to complex fixed-point numbers.
CxToIntConvert fixed-point numbers to complex fixed-point numbers.
IntToFixConvert fixed-point numbers to complex fixed-point numbers.
IntToCxConvert fixed-point numbers to complex fixed-point numbers.
IIRstars are identical to their SDF counterparts.
AllpassAn allpass filter with one pole and one zero. The location of these is given by the "polezero" input.
BiquadA two-pole, two-zero IIR filter (a biquad).
CombA comb filter with a one-pole lowpass filter in the delay loop.
BiquadDSPlayA two-pole, two zero IIR filter (a biquad). This biquad is tailored to use the coefficients from the DSPlay filter design tool. If DSPlay gives the coefficients: A B C D E then define the parameters as follows: a=A, b=B, c=C, d=-(D+1), e = -E. This only works if a, b, c, d, and e, are in the range [-1,1). The default coefficients implement a low pass filter.
FIRA finite impulse response (FIR) filter. Coefficients are specified by the taps parameter. The default coefficients give an 8th order, linear-phase, lowpass filter. To read coefficients from a file, replace the default coefficients with
filename, preferably specifying a complete path. Polyphase multirate filtering is also supported.
LMSAn adaptive filter using the LMS adaptation algorithm. The initial coefficients are given by the coef parameter. The default initial coefficients give an 8th order, linear phase lowpass filter. To read default coefficients from a file, replace the default coefficients with
filename, preferably specifying a complete path. This star supports decimation, but not interpolation.
LMSGangedA LMS filter were the coefficients from the adaptive filter are used to run a FIR filter in parallel. The initial coefficients default to a lowpass filter of order 8.
LMSRxA Complex LMS filter
RaisedCosAn FIR filter with a magnitude frequency response shaped like the standard raised cosine used in digital communications. See the
SDFRaisedCosinestar for more information.
LMSOscDetare identical to their SDF counterparts.
FFTCxCompute the discrete-time Fourier transform of a complex input using the fast Fourier transform (FFT) algorithm. The parameter order (default 8) is the transform size. The parameter direction (default 1) is 1 for forward, -1 for the inverse FFT.
WindowGenerate standard window functions or periodic repetitions of standard window functions. The possible functions are
Kaiser. One period of samples is produced on each firing.