XC56303PV66 Motorola, XC56303PV66 Datasheet
XC56303PV66
Available stocks
Related parts for XC56303PV66
XC56303PV66 Summary of contents
Page 1
Interfacing a Data Acquisition System to the DSP56303 Application Note Mihai V. Micea Vladimir Cretu and Dan Chiciudean Rev. 0, 12/2000 by AN2087/D ...
Page 2
... Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur ...
Page 3
Abstract and Contents This paper discusses the hardware and software aspects of interfacing a data acquisition system (DAQ) to the DSP56303 digital signal processor. Included are descriptions of a generic DAQ system, a particular DAQ system connected to the DSP56303, ...
Page 4
Interfacing a Data Acquisition System to the DSP56303 ...
Page 5
Introduction Digital data processing and control systems have become ubiquitous in modern daily life. Information from a wide variety of environmental sources, including sound waves, light, temperature, gas pressure, radiation, and mechanical movement, is converted to digital signals which ...
Page 6
Description of a Generic DAQ System This section describes the operation of a generic DAQ system and the parameters used to evaluate DAQ system performance. 2.1 DAQ Operation Figure block diagram of a generic input-only data ...
Page 7
Asserting EOC has the following two results: a) The data buffer’s write enable signal is asserted, latching the new conversion result in the data buffer. b) The DSP interrupt signal (IRQ) is asserted. The DSP interrupt handler responds to ...
Page 8
Table 2 lists the parameters for a particular ADC. Parameter Sampling Rate Full Scale Range Resolution One example of an actual ADC which is used on the DSP56303 and DSP56307 Evaluation Modules (EVMs) is Crystal Semiconductor’s CS421x audio CODEC family. ...
Page 9
... A host computer which functions as a graphical user interface and provides an interactive system control platform. The DAQ-DSP connection is described in detail in this paper. The DSP-host computer connection is described in Motorola application note, ECP Standard Parallel Interface for DSP56300 Devices (order number AN2085/D). 3.2 DAQ System Architecture and Operation Figure 4 on page diagram of the DAQ employed in the proposed system ...
Page 10
V ADS774 N Figure 4. Example System DAQ Architecture The Burr-Brown ADS774 was selected as the analog-to-digital component of the DAQ because of its simple interface and command requirements as well as performance that is very well-suited to illustrate the ...
Page 11
R/C Status DB11–DB0 Data Valid Symbol t Low R/C pulse width HRL t Status delay from R Conversion time conversion t Data valid after R/C low HDR t Status delay after data valid HS The ADS774 Status pin, ...
Page 12
Example DAQ-DSP System—Implementation Details The interface between the DSP56303 and the DAQ in the example system is shown in Figure 6. The interface uses the DSP’s Port A lines as follows: A Read signal simultaneously initiates a ...
Page 13
Data acquisition is fully controlled by DSP software. Code Example 1 provides a general framework for a data acquisition and processing program on the DSP56303. This program initializes chip parameters (chip clock and PLL, interrupts and Port A access), sets ...
Page 14
Code Example 1 (Continued). Data Acquisition and Processing Program on the DSP56303 movep #305,X:M_TCPR0 movep #$302a05,X:M_TCSR0 ; Initialize Timer0 Control Register and start ; ; Other routines can be added here to process the data acquired in the ;; 512-word ...
Page 15
The data buffer in this program can be configured and used in several ways. One simple approach is to use two data buffers—one for current acquisition and storing operations in the timer interrupt handler, and one for data processing in ...
Page 16
Case Study: Digital Oscilloscope Using the DSP56303 To illustrate the practical application of our example system, this section describes the design of a digital oscilloscope using the DSP56303, with a host computer providing a graphical user interface and general ...
Page 17
Table 6. Digital Oscilloscope Parameters (Continued) Parameter General features Signal display modes Variable time base Synchronization modes Amplitude calculation Frequency/period calculation Parameters calculated and displayed continuously 5.2 Graphical User Interface The graphical user interface emulates the display and control panel ...
Page 18
Figure 8. Digital Oscilloscope Graphical User Interface The oscilloscope GUI has separate windows for the signal, frequency spectrum, and control panel. 5.2.1 Signal Display Window The signal display window displays the acquired signal in both real-time mode (RUN Mode) and ...
Page 19
Signal Spectrum Window The oscilloscope calculates a FFT over a 512-sample buffer and displays the frequency components on the signal spectrum window. An interactive vertical cursor, which can be manipulated by either the mouse or a slide bar in ...
Page 20
Code Listing 1 (Continued). Oscilloscope Initialization ; Variables used in the program. ; BUFFER equ $000000 BUFFLEN equ 511 DAQ equ $002000 HOSTCLK equ 8 PERIPHCLK equ 9 PERIPHACK equ 10 nACKREVERSE equ 11 HOSTACK equ 12 nREVERSEREQUEST equ 13 ...
Page 21
Main Program Code Listing listing of the main program for the digital oscilloscope. Figure 9 on page flowchart of the main program. The jagged arrows in the figure represent asynchronous events, which imply ...
Page 22
... Macro inputs: ;; POINTS—number of FFT points; ;; BUFFER—start of input data buffers ;; (normally ordered) ;; COEF—start of sine/cosine table. ;; Macro outputs: POINTS locations ;; (NOTE: Output data is bit-reversed.) ;; X:BUFFER—real values ;; Y:BUFFER—imaginary values ; Call the ‘bitrev’ macro developed by ;; Motorola, Incorporated, for the ...
Page 23
... Syncro—Synchronizes the input signal on the rising or falling edge at a specified voltage level. 2. Acq_buffer—Buffers a set of input signal samples. 3. Min_max—Calculates the minimum and maximum values in the buffer. 4. —DSP56300 library routines developed by Motorola to perform fftr2a and bitrev FFT calculations. The and ...
Page 24
Syncro routine activated SYNC_LEVEL Samples acquired and ignored TRIG_TYPE = 0 (positive triggering) Figure 10. Signal Synchronization Procedure The Syncro routine is given in Code Listing 3. Code Listing 3. Signal Synchronization Routine (Syncro) Syncro move #0,X0 move X:TRIG_TYPE,A0 jset ...
Page 25
Code Listing 3 (Continued). Signal Synchronization Routine (Syncro) Negative jsr Counts jset #0,B,_end_negative jsr Acq_sample clr B move X:SYNC_LEVEL,B0 inc B cmp B,A jle Negative _end_negative rts Counts clr A move X0,A0 inc A nop move A0,X0 clr B move ...
Page 26
... DSP56303 Port A peripheral. This second-level routine is called by the routines. Acq_buffer 22 Interfacing a Data Acquisition System to the DSP56303 . The results are stored in the variables and macros developed by Motorola to perform fast Fourier bitrev macro is bit-reversed, the bitrev and MIN_VAL MAX_VAL macro is called to unscramble the ...
Page 27
... DSP and to communicate the results back to the host computer, the Extended Capabilities Port (ECP) parallel interface standard is used as the communication between the DSP56303 and the host computer. A more complete description of the implementation of this interface can be found in Motorola application note, ECP Standard Parallel Interface for DSP56300 Devices (order number AN2085/D). ...
Page 28
... DSP56300 24-bit Digital Signal Processor Family Manual(ordernumber DSP56303 User’s Manual (order number DSP56303 Evaluation Module User’s Manual (ordernumber Motorola DSP Assembler Reference Manual, Motorola, 1999. Digital Signal Processing Principles, Algorithms and Applications Proakis and D. G. Manolakis, 3rd edition, Prentice-Hall, 1996. ...