Microchip Technology MA300014 Data Sheet

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dsPIC30F
DS70043F-page 54
©
 2005 Microchip Technology Inc.
• The following window functions are supported:
- Rectangular
- Hanning (Hann)
- Hamming
- Triangular
- Blackman
- Exact Blackman
- 3  Term  Cosine
- 3 Term Cosine with continuous 3rd Derivative
- Minimum 3 Term Cosine
- 4  Term  Cosine
- 4 Term Cosine with continuous 5th Derivative
- Minimum 4 Term Cosine
- Good 4 Term Blackman Harris
- Harris Flat Top
- Kaiser
- Dolph-Tschebyscheff
- Taylor
- Gaussian
• Reports show design details such as window 
coefficients and Impulse Response prior to 
multiplying by the window function
Infinite Impulse Response Filter Design
• Lowpass, Highpass, Bandpass and Bandstop 
Filters
• Filter orders up to 10 for Lowpass and Highpass 
Filters
• Filter orders up to 20 for Bandpass and Bandstop 
Filters
• Five Analog Prototype Filters are available:
- Butterworth
- Tschebyscheff
- Inverse Tschebyscheff
- Elliptic
- Bessel
• Digital Transformations are performed by Bilinear 
Transformation Method
• Reports show design details such as all 
transformations from normalized lowpass filter to 
desired filter
Code Generation Features
• Generated files are compliant with the Microchip 
dsPIC30F C30 Compiler, Assembler and Linker
• Choice of placement of coefficients in Program 
Space or Data Space
• C wrapper/header code generation
Graphs
• Magnitude Response vs. Frequency
• Log Magnitude vs. Frequency
• Phase Response vs. Frequency
• Group Delay vs. Frequency
• Impulse Response vs. Time (per sample)
• Step Response vs. Time (per sample)
• Pole and Zero Locations (IIR only)
12.6
Real-Time Operating Systems
Real-Time Operating System (RTOS) solutions for the
dsPIC30F product family provide the necessary
function calls and operating system routines to enable
you to write efficient C and/or assembly code for multi-
tasking applications. RTOS is especially suited for
applications where program, and, more importantly,
data memory resources, are limited. Configurable and
optimized kernels support various RTOS application
requirements.
The dsPIC30F RTOS solutions are three-tiered:
• CMX-RTX™ full-featured fully-preemptive 
multitasking RTOS
• CMX-Tiny+™ fully-preemptive scaled-down 
version of CMX-RTX
• CMX-Scheduler™ fully-preemptive, multitasking, 
mini RTOS (FREE)
12.6.1
CMX-RTX™
In some cases, well-structured linear programming is
sufficient for a product. However, in most cases,
programmers appreciate not having to worry about
structuring their code to perform all necessary tasks in
a timely manner. CMX-RTX helps by allowing tasks
(pieces of code that do specific duties) to run quasi-
concurrently. That is, tasks seem to run at the same
time – doing many specific jobs simultaneously
CMX-RTX takes the headaches out of real-time
programming. The software lets the programmer
concentrate on the overall application while it takes
care of the details. CMX-RTX lets you finish projects
faster and more efficiently.
Some real-time operating systems offer only
cooperative scheduling, which means that the running
task is required to call the scheduler to perform a task
switch. Others offer time slicing in which each task runs
for a given period of time and then must switch tasks,
regardless of conditions. Still others claim to be fully
preemptive, yet they do not allow any interrupt to cause
a preemption. All of these models will fail at one point
or another.