\
CDB5461
CDB5461 Evaluation Board and Software
Features
General Description
z Direct
The CDB5461 is an inexpensive tool designed to evaluate the functionality and performance of the CS5461.
The CS5461 Data Sheet is supplied in conjunction with
the CDB5461 evaluation board.
Shunt Sensor and Current
Transformer Interface
z RS-232 Serial Communication with PC
z On-board 8051 Microcontroller
z On-board Voltage Reference
z Lab Windows/CVITM Evaluation Software
-
Register Setup & Chip Control
FFT Analysis
Time Domain Analysis
Noise Histogram Analysis
z On-board
Data SRAM
z Integrated RS-232 Test Mode
z “Auto-Boot” Demo with serial EEPROM
The evaluation board includes an LT1019 voltage reference, an 8051 microcontroller, an RS232 transceiver,
and firmware. The 8051 controls the serial communication between the evaluation board and the PC via the
firmware, enabling quick and easy access to all of the
CS5461’s registers and functions.
The CDB5461 includes software for Data Capture, Time
Domain Analysis, Histogram Analysis, and Frequency
Domain Analysis.
ORDERING INFORMATION
CDB5461
VA+
VACRYSTAL
4.096 MHz
VIN+
SERIAL
EEPROM
TEST
SWITCHES
Vu+
CRYSTAL
20.0 MHz
RS232
TRANSCEIVER
8051
ISP
CS5461
CS
SDI
VIN-
SDO
SCLK
INT
EDIR
EOUT
IIN+
IIN
-
VD+
GND
Evaluation Board
8051
Microcontroller
32k × 8
SRAM
RESET
CIRCUITRY
VREF
IN OUT
REF
AGND
Cirrus Logic, Inc.
http://www.cirrus.com
VOLTAGE
REFERENCE
LEDs
Copyright © Cirrus Logic, Inc. 2004
(All Rights Reserved)
APR ‘04
DS487DB4
CDB5461
TABLE OF CONTENTS
1. HARDWARE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Evaluation Board Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.1 Analog Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.2 Digital Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.3 Power Supply Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 Using the Evaluation Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. SOFTWARE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Installation Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Using the Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 Selecting and Testing a COM Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4 Register Access in the Setup Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4.1 Refresh Screen Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4.2 CS5461 Crystal Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4.3 Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4.4 Mask Register / Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.4.5 Cycle Count / PulseRateE / PulseRateF / PulseWidth / VSAGlevel /
VSAGduration / Time Base Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.4.6 Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.5 Calibration Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.5.1 Offset / Gain Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.5.2 Performing Calibrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.6 Conversion Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.6.1 Single Conversion Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.6.2 Continuous Conversions Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.6.3 Re-Initialize Serial Port Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.6.4 Standby / Sleep Mode Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.6.5 Power Up Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.7 Viewing Pulse Rate Output Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.7.1 Integration Period Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.7.2 Periods To Average Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.7.3 Start Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.8 Data Collection Window Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.8.1 Time Domain / FFT / Histogram Selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.8.2 Collect Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.8.3 Config Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.8.4 Output Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.8.5 Zoom Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.8.6 Channel Select Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.9 Config Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.9.1 Number of Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.9.2 Average . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.9.3 FFT Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.9.4 Histogram Bin Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.9.5 Pages to Collect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.9.6 Data to Collect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.9.7 Accept Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.10 Collecting Data Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.11 Retrieving Saved Data From a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.12 Analyzing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2
CDB5461
2.13 Histogram Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.13.1 BIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.13.2 MAGNITUDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.13.3 MAXIMUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.13.4 MEAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.13.5 MINIMUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.13.6 STD. DEV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.13.7 VARIANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.14 Frequency Domain Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.14.1 FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.14.2 MAGNITUDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.14.3 S/D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.14.4 S/N+D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.14.5 SNR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.14.6 S/PN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.14.7 # of AVG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.15 Time Domain Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.15.1 COUNT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.15.2 MAGNITUDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.15.3 MAXIMUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.15.4 MINIMUM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
LIST OF FIGURES
Figure 1. Start-Up Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 2. Setup Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 3. Calibration Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 4. Conversion Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 5. Pulse Rate Output Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 6. Time Domain Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 7. FFT Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 8. Histogram Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 9. Analog Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 10. Digital Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 11. Power Supply Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 12. Silkscreen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 13. Circuit Side. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 14. Solder Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
LIST OF TABLES
Table 1. Reference Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Table 2. Power Supply Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Table 3. Header, Jumper, and DIP Switch Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Table 4. DIP Switch S1 Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3
CDB5461
1. HARDWARE
1.1 Introduction
The CDB5461 evaluation board provides a
quick means of evaluating the CS5461 Power
Meter IC. The CDB5461 evaluation board’s
analog section operates from a single +5V
power supply. The evaluation board interfaces
the CS5461 to an IBM® compatible PC via an
RS-232 interface. Additional analysis software
provides easy access to the internal registers
of the CS5461, and provides a means to measure and display the performance in the time
and frequency domains.
1.2 Evaluation Board Overview
The board is partitioned into two main sections: analog and digital. The analog section
consists of the CS5461 and a precision voltage reference. The digital section consists of
the 8051 microcontroller, 32 Kilobytes of
SRAM, the hardware test switches, the reset
circuitry, and the RS-232 interface. The board
also has a user friendly power supply connection.
1.2.1 Analog Section
The CS5461 is designed to accurately measure and calculate: Energy, Instantaneous
Power, IRMS, and VRMS while operating from a
4.096 MHz crystal.
As shown in Figure 9,
there are four BNC connectors (J6, J7, J8, J9)
provided for converter input connections. A
Shunt Sensor or Current Transformer can be
connected to the converter’s current inputs via
J9 (IIN+) and J8 (IIN-). A voltage divider can
be connected to the converter’s voltage input
via J6 (VIN+) and J7 (VIN-). A simple RC network filters the sensor’s output to reduce any
interference picked up by the input leads. The
4
3 dB corner of the filter is approximately
50 kHz differential and common mode.
The evaluation board provides three voltage
reference options: On-chip, On-board, and External, as shown in Figure 9. Table 1 illustrates
the options available. With J18’s jumpers in
position REFOUT, the CS5461’s on-chip reference provides 2.5V. With J18’s jumpers in position LT1019, the LT1019 provides 2.5V (the
LT1019 was chosen for its low drift, typically
5 ppm/°C). If needed R29 can be populated
and use to dial-in a specific reference voltage
just above or below 2.5V. By setting J18’s
jumpers to position REF+, VREFIN will be set
to the external voltage at J26’s REF+ and VAinputs.
Reference
Description
J18
LT1019
Selects on board
LT1019 Reference
(5ppm/°C)
O
O
O
O LT1019
O REF+
O REFOUT
REF+
Selects external
reference
O
O
O
O LT1019
O REF+
O REFOUT
REFOUT
Selects the reference
supplied by CS5461
O
O
O
O LT1019
O REF+
O REFOUT
Table 1. Reference Selection
The CS5461 serial interfaces are SPITM and
MicrowireTM compatible. The interface control
lines (CS, SDI, SDO, and SCLK) are connected to the 8051 microcontroller via Port 1. To interface an external microcontroller, these
control lines are also connected to J19 (Header 19). However to accomplish this, the evaluation board must be modified in one of three
ways: 1) cut the interface control traces going
to the microcontroller, 2) remove resistors 24,
23, 22, and 21, or 3) remove the microcontroller.
CDB5461
1.2.2 Digital Section
The schematics for the digital section are
shown in Figure 10 on page 22. The digital
section contains the microcontroller, test
switches, a Maxim MAX3232 interface chip,
32K bytes of SRAM, and one serial EEPROM.
The test switches aid in debugging communication problems between the CDB5461 and
the PC. The microcontroller derives its clock
from a 20.0 MHz crystal. From this, The RS232 data conversion IC (10) is configured to
communicate via RS-232 at 9600 baud, no
parity, 8-bit data, and 1 stop bit.
1.2.3 Power Supply Section
Figure 11 on page 23 illustrates the power
supply connections to the evaluation board.
The VA+ post supplies the positive analog
section of the evaluation board, the LT1019,
and the ADC. The VA- post supplies the negative analog voltage circuitry. This terminal is
grounded when powering the CDB5461 from a
single +5 Volt analog supply. The VD+ post
supplies the digital section of the ADC and level shifter. The Vu+ post supplies the digital
section of the evaluation board, the 8051, the
reset circuitry, and the RS-232 interface cir-
Power Supplies
Analog
Digital
VA+
cuitry. The board’s digital section, supplied via
Vu+ post, must be +5 Volts only. Table 2
shows the various power connections with the
required jumper settings on J12 and J11.
1.3 Using the Evaluation Board
The CS5461 contains a programmable gain
amplifier (PGA), two ∆Σ modulators, two high
rate filters, an on-chip reference, and power
calculation engine to compute Energy, VRMS,
IRMS, and Instantaneous Power. The PGA
sets the input levels of the current channel at
either 50 mVRMS or 250 mVRMS (for VREFIN =
2.5 V). The on-chip reference can provide the
necessary 2.5 V reference. This output (VREFOUT) is used to supply the VREFIN pin with
2.5 V. The ∆Σ modulators and high rate digital
filter allow the user to measure instantaneous
voltage, current, and power at a output word
rate of 4000 Hz when a 4.096 MHz clock
source is used.
Table 3 on page 6 describes the various headers, jumpers and DIP switches on the
CDB5461 evaluation board. DIP switch S1 is
used to control the 8051. Table 4 on page 7 illustrates the various settings of the DIP switch
S1. The S1-3 switch should be set to the
Power Post Connections
VAGND
VD+
Jumpers
Vu+
J12
+5V
+5V
+5
NC
GND
+5
NC
Vu+ O
VD+ O
VD+ O
VA+ O
+5V
+3V
+5
NC
GND
+3
+5
Vu+ O
VD+ O
VD+ O
VA+ O
J11
O
O
O
O
VDDD
VDDD
D+
D+
VA- O
A- O
O GND
O GND
O
O
O
O
VDDD
VDDD
D+
D+
VA- O
A- O
O GND
O GND
Table 2. Power Supply Connections
5
CDB5461
Name
Function Description
Default Setting
J13
Sets VIN+ on the CS5461 to J6 or GND.
VIN+ Set to BNC J6
O
O
O VIN+
O GND
J14
Sets VIN- on the CS5461 to J7 or GND.
VIN- Set to BNC J7
O
O
O VINO GND
J11
Used to switch VA-, A-, and GND. Refer toTable 2
on page 5
Negative Analog
Power Supply Set to
0V
VA- O
A- O
O GND
O GND
J18
Used to switch the VREFIN from external J26
header, to the on board LT1019 reference, or to
theCS5461 on-chip reference VREFOUT.
J12
Used to switch VU+, VD+, and VA+ to VDDD and/or Digital Power Supply
D+. Refer to Table 2 on page 5
Set to +5V
J17
VREFIN Set to onchip reference
VREFOUT
O
O
O
O LT1019
O REF+
O REFOUT
Vu+ O
VD+ O
VD+ O
VA+ O
Used to connect an external micro-controller.
Connected to 8051
Used in conjunction with the self test modes to test
RS-232 Set to Normal
the UART/RS-232 communication link between the
Mode
microcontroller and a PC.
O
O
O
O
VDDD
VDDD
D+
D+
NC
O
O
O
O
J17
J19
J15
Sets IIN- on the CS5461 to J8 or GND.
IIN- Set to BNC J8
O
O
O IINO GND
J16
Sets IIN+ on the CS5461 to J9 or GND.
IIN+ Set to BNC J9
O
O
O IIN+
O GND
J23
Used to switch XIN on the CS5461 to J19 when an XIN Set for on-board
external micro-controller is used.
4.096 MHz XTAL
O
O
O GND
O XIN
JP2
Used to connect PFMON pin on the CS5461 to
monitor Power Supply VA+
PFMON Set Monitor
VA+
O
O JP2
J24
Used to connect the RESET Button to the CS5461
RESET Set connected to CS5461
O
O J24
J25
Used to connect the RESET Button to the 8051
RESET Set connected to 8051
O
O J25
S1
DIP switch to control 8051 (See Table 4)
S1-1 is used to enable auto-boot mode
S1-2 is used to select crystal to 8051
S1-3 is used to select RS-232 test mode
J29
J21
J22
Enables the D1 LEDs
Allows LEDs D7 and D6 to indicate pulses on
/EOUT and /EDIR.
Allows LEDs D2 and D3 to indicate pulses on
/FOUT.
S1-1 Auto-Boot off
S1-2 Set 20 MHz
S1-3 Set Normal
1
2
3
OPEN
Enable LEDs
O
O J29
Disable LEDs
O
O J21
Disable LEDs
O
O J22
Disable LED
O
O J27
O
O J10
J27
Allows LEDs D8 to indicate pulses on /INT.
J10
Used to disconnect XTAL1 input on microcontroller
Use on-board crystal
from off-board oscillator input.
Table 3. Header, Jumper, and DIP Switch Descriptions
6
Default Jumpers
CDB5461
8051 Mode
8051 in Normal Operating Mode
S1-1 OPEN
S1-2 CLOSED 20 MHz Crystal
S1-3 OPEN
8051 in Normal Operation Mode
S1-1 OPEN
S1-2 OPEN 11.059 MHz Crystal
S1-3 OPEN
8051 in Test Mode
S1-1 OPEN
S1-2 CLOSED 20 MHz Crystal
S1-3 CLOSED
8051 in Test Mode
S1-1 OPEN
S1-2 OPEN 11.059 MHz Crystal
S1-3 CLOSED
Auto-Boot Mode
S1-1 CLOSED
S1-2 CLOSED
S1-3 OPEN
S1
1
2
3
OPEN
1
2
3
OPEN
1
2
2
When the CDB5461 Evaluation Board is sent
from the factory, the EEPROM is programmed
with the following CS5461 command/data sequence:
40 00 00 61
;In configuration Register, turn
high- pass filters on, set K = 1.
4C 10 00 00
;Set Pulse Rate Register to
32768 Hz.
E8
;Start continuous conversions.
78 00 01 00
;Write stop bit to CS5461 to termi-
3
OPEN
1
inputs, the CS5461 will issue pulses on the
/EOUT and /EDIR pins. The J24 header must
be shorted for auto-boot to work.
3
nate autoboot sequence.
OPEN
1
2
3
OPEN
Table 4. DIP Switch S1 Setting
OPEN position for normal operation. When
testing the RS-232 link in the PC software,
close S1-3. The S1-2 switch selects the crystal
source for the 8051. There are two crystal options available, 11.059 MHz and 20 MHz. If
S1-2 is OPEN the 11.059 MHz crystal is selected, and when S1-2 is CLOSED the 20 MHz
crystal is selected.
If S1-1 is closed, the CS5461 operates in autoboot mode. When in auto-boot mode, a hardware reset (press on S2) will cause the
CS5461 to boot up using the serial data from
the serial EEPROM on the board (U9). The
EEPROM must be programmed prior to the
auto-boot sequence. The EEPROM does
come pre-programmed with a valid boot-up
sequence. This sequence programs the
CS5461 for continuous conversion mode. If
voltage and current signals are applied to the
The auto-boot sequence runs with no assistance from the 8051 microcontroller. The user
can verify this by disconnecting power from
the board, pulling the microcontroller out of its
socket, then power on again and run in autoboot mode. See the CS5461 data sheet for
more details on auto-boot.
2. SOFTWARE
The evaluation board comes with software and
RS-232 cable to link the evaluation board to
the PC. The evaluation software was developed with Lab Windows®/CVI®, a software development
package
from
National
Instruments. The software was designed to
run under Windows®95 or later, and requires
about 3MB of hard drive space (2MB for the
CVI® Run-Time Engine, and 1MB for the evaluation software). After installing the software,
read the readme.txt file for any last minute updates or changes. More sophisticated analysis
software can be developed by purchasing the
LabWindows® development package from National Instruments.
7
CDB5461
2.1 Installation Procedure
1) Turn on the PC, running Windows®95 or
later.
2) Insert the installation CD into the PC and
open the cvidistkit.EVL5461 folder.
3) Run Windows® Installer executable. For
Windows 9x systems, run ‘instmsi.exe’; for
later systems, run ‘instmsiw.exe’.
4) Double-click ‘EVL5461.msi’ to begin installation.
5) Follow the installation directions on the
screen.
6) If it has not already been installed on the
PC, the user will be prompted to enter the
directory in which to install the CVI® RunTime Engine. The Run-Time Engine manages executables created with Lab Windows®/CVI®. If the default directory is
acceptable, select OK and the Run-Time
EngineTM will be installed there.
7) After the Run-Time EngineTM is installed,
the user is prompted to enter the directory
in which to install the CDB5461 software.
Select OK to accept the default directory.
8) Once the program is installed, it can be run
by double-clicking on the EVL5461 icon, or
through the Start menu.
Notes: The software is written to run with 640 x 480
resolution; however, it will work with 1024 x 768
resolution. If the user interface appears to be
small, the user might consider setting the
display settings to 640 x 480. (640x480 was
chosen to accommodate a variety of
computers).
2.2 Using the Software
Before launching the software, the user should
set up the CDB5461 evaluation board by using
the correct jumper and DIP switch settings as
described in Table 4, and connect it to an open
COM port on the PC using the RS-232 serial
8
cable. Once the board is powered on, the user
can start the software package.
When the software is launched, the Start-Up
window appears first (Figure 1). This window
contains information concerning the software’s
title, revision number, copyright date, etc. At
the top of the screen is a menu bar which displays user options. The menu bar item Menu is
initially disabled to prevent conflicts with other
serial communications devices, such as the
mouse or a modem. After selecting a COM
port, the Menu item will become available.
2.3 Selecting and Testing a COM Port
Upon start-up, the user is prompted to select
the serial communications port which will interface to the CDB5461 board. To select the
COM port, pull down the Setup menu option,
and select either COM1 or COM2 (the DISK
option is used for previously saved files, and is
discussed later). Testing the COM port to verify communication between the PC and the
evaluation board is not necessary, but can help
to troubleshoot some problems. The procedure for testing the communication link follows.
1) Pull down the Setup menu option again,
and select TEST RS-232.
2) When prompted, set DIP switch 1 (the leftmost DIP switch) to the closed position, reset the board, and press OK to perform the
test.
3) If the test passes, set DIP switch 1 to the
open position, and reset the board to return
to normal operating mode.
4) If the test fails, check the serial port connections, power connections, jumpers, and
DIP switch settings on the board, and run
the test again from step 1.
Once the serial link is established between the
PC and the evaluation board, the user is ready
CDB5461
to access the internal registers of the CS5461,
collect data, and perform analysis on the collected data.
Figure 1. Start-Up Window
2.4 Register Access in the Setup
Window
The Evaluation software provides access to
the CS5461’s internal registers in the Setup
Window (Figure 2). The user can enter the
Setup Window by pulling down Menu and selecting Setup Window, or by pressing F2 on
the keyboard.
In the Setup Window, all of the CS5461’s registers are displayed in hexadecimal notation,
and also decoded to provide easier readability.
Refer to the CS5461 data sheet for information
on register functionality and definitions.
2.4.1 Refresh Screen Button
The Refresh Screen button will update the
contents of the screen by reading all the register values from the part. This usually takes a
couple of seconds, but it is a good idea to
press the Refresh Screen button when entering the Setup Window, or after modifying any
registers to reflect the current status of the
part.
2.4.2 CS5461 Crystal Frequency
The CS5461 accepts a wide range of crystal
input frequencies, and can therefore run at
many different sample rates. The crystal frequency being used on the CS5461 should be
9
CDB5461
Figure 2. Setup Window
entered in this box to provide accurate frequency calculations in the FFT window. This
will also help the software decide which functions can be performed reliably with the evaluation system.
Output function should be set to the default Active Low, and the Eout / Edir Function should
be set to the default Normal. This applies only
to the CDB5461 evaluation system, and not to
the CS5461 chip itself.
2.4.3 Configuration Register
2.4.4 Mask Register / Status Register
In the Configuration Register box, the contents
of the Configuration Register can be modified
by typing a hexadecimal value in the HEX:
box, or by changing any of the values below
the HEX: box to the desired settings. Although
the CDB5461 software allows the user to modify any of the bits in the Configuration Register,
changing certain bits may cause the software
and board to behave erratically. For the evaluation system to function properly, the Interrupt
The Mask and Status Registers are displayed
in hexadecimal and decoded in this box to indicate each bit’s function. The Mask Register
can be modified by typing a value in the HEX:
box, or by checking the appropriate check boxes for the bits that are to be masked. The Status Register cannot be directly modified. It can
only be reset by pressing the Clear Status
Register Button. The HEX: box for this register, and the LEDs are display only. A LED that
10
CDB5461
is on means that the corresponding bit in the
Status Register is set (except the Invalid Command bit, which is inverted). The value present
in the Mask register may be changed by the
software during certain operations to provide
correct functionality of the CDB5461 board.
2.4.5 Cycle Count / PulseRateE /
PulseRateF / PulseWidth / VSAGlevel /
VSAGduration / Time Base Registers
These boxes display the values corresponding
register in both hexadecimal and decimal format. Each register can be modified by typing a
value in the corresponding Value: or HEX:
box.
2.4.6 Control Register
The Control Register contains various bits
used to activate or terminate various features
of the CS5461. Refer to the CS5461 data
sheet for description of the bits. The user is
able to turn each bit on or off individually. The
value of the Control Register is displayed in
HEX. Most of the Control Register bits are reserved or unused. Only the usable bits are
displayed in the Setup Window.
Figure 3. Calibration Window
2.5 Calibration Window
The Calibration Window is used to display and
write to the CS5461 offset and gain calibration
registers. The user is also able to initiate the
CS5461’s calibration sequences that are used
to set the calibration values. Both AC and DC
calibrations can be run for offset and gain, for
either the voltage channel or the current channel, or both simultaneously. The user should
refer to the CS5461 data sheet for more details
on calibration.
11
CDB5461
2.5.1 Offset / Gain Register
2.5.2.1. Offset Calibrations:
In the Offset and Gain Register boxes, the offset and gain registers for both channels are
displayed in hexadecimal and decimal. These
registers can all be modified directly by typing
the desired value in the hexadecimal display
boxes. There are two types of offset registers:
DC offset and AC offset. The AC offset registers only affect the RMS-register values. The
RMS offset registers only hold positive values
between 0 and +1. The DC offset register is a
two’s complement number whose value ranges from -1 to +1.
1) Ground the channel(s) you want to calibrate directly at the channel header(s). J13
and J14 for the voltage channel, and J15
and J16 for the current channel. The channel(s) could also be grounded directly at
the BNC connectors.
2.5.2 Performing Calibrations
2.5.2.2. Gain Calibrations:
Offset and gain calibrations can be performed
on both the voltage and current channels of
the CS5461. It is generally a good idea to software-reset the CS5461 before running calibrations, because the values in the calibration
registers will affect the results of the calibration. A software reset will reset these registers
back to the default values of zero offset and
unity gain. Offset calibration should be performed before gain calibration to ensure accurate results.
1) Attach an AC or DC calibration signal to the
BNC connector(s), and make sure the corresponding channel headers (J13, J14,
J15, and J16) are set to the input position.
12
2) Press the corresponding AC or DC offset
calibrate button (Cal V, Cal I, or Cal Both)
in the Offset Register boxes.
3) The calibration value(s) will automatically
update when the calibration is completed.
2) Press the corresponding AC or DC gain
calibrate button (Cal V, Cal I, or Cal Both)
in the Gain Register box.
3) The calibration value(s) will automatically
update when the calibration is completed.
The Calibration Window also contains the
Power Offset Register display and adjustment.
The user can read and write the value in the
Power Offset Register.
CDB5461
2.6 Conversion Window
The Conversion Window (Figure 4) allows the
user to see the results of single and continuous conversions, perform data averaging, utilize the power-saving modes of the CS5461,
and reset the CS5461’s serial port. The Conversion Window can be accessed by pulling
down the Menu option, and selecting Conversion Window, or by pressing F3.
2.6.1 Single Conversion Button
On pressing this button, single conversions
will be performed repeatedly until the user
presses the Stop button. After each conversion is complete, the Result data column will
update with the values present in each data
register. The Mean and Standard Deviation
columns will update every N cycles, where N is
the number in the Samples to Average box. It
may can take many collection cycles after
pressing the Stop button before the data actually stops being collected.
2.6.2 Continuous Conversions Button
This button functions similarly to the Single
Conversion button, except that continuous
conversions are performed instead. The data
on the screen is updated in the same fashion,
and the Stop button terminates this action.
There are some speed limitations when performing this function, and if any of these limitations are exceeded, the user will be prompted
to change some settings before proceeding.
2.6.3 Re-Initialize Serial Port Button
When this button is pressed, the software will
send the synchronization sequence discussed
in the CS5461 data sheet to the part. This sequence brings the CS5461’s serial port back to
Figure 4. Conversion Window
13
CDB5461
a known state. It does not reset any of the registers in the part.
2.6.4 Standby / Sleep Mode Buttons
When these buttons are pressed, the part will
enter either Standby or Sleep power saving
modes. To return to normal mode, use the
Power Up button.
2.7.1 Integration Period Box
This box allows the user to select the length of
time which pulses will be collected over.
2.7.2 Periods To Average Box
This box allows the user to average a number
of integration periods together.
2.7.3 Start Button
2.6.5 Power Up Button
This button is used to send the Power Up/Halt
command to the CS5461. The part will return
to normal operating mode and halt any conversions that are being done at this time.
2.7 Viewing Pulse Rate Output Data
The CS5461 features a pulse-rate energy output. The CDB5461 has the capability to demonstrate the functionality of this output in the
Pulse Rate Output Window (Figure 5). The
Pulse Rate Output Window can be accessed
by pressing the F4 key, or by pulling down the
Menu option, and selecting Pulse Rate Window.
When the Start button is pressed, the
CDB5461 will capture pulse rate data according to the values in the Integration Period and
Periods to Average boxes. After each integration period, the Pulse Count and Frequency
columns will be updated. The Average Freq.
and Standard Deviation columns will only be
updated after all of the integrations have been
collected. The software stops collecting data
when the user presses the Stop button, or
when the data collection is finished. Due to
speed limitations of the on-board microcontroller, some higher pulse rates cannot be accurately collected. If the pulse rate is too high, a
warning message will appear.
Figure 5. Pulse Rate Output Window
14
CDB5461
2.8 Data Collection Window Overview
The Data Collection Window (Figure 6,
Figure 7, and Figure 8) allows the user to collect sample sets of data from the CS5461 and
analyze them using time domain, FFT, and
histogram plots. The Data Collection Window
is accessible through the Menu option, or by
pressing F5.
2.8.1 Time Domain / FFT / Histogram
Selector
This menu selects the type of data processing
to perform on the collected data and display in
the plot area. Refer to the section on Analyzing
Data for more information.
2.8.2 Collect Button
This button will collect data from the part, to be
analyzed in the plot area. See the section on
Collecting Data Sets for more information.
2.8.3 Config Button
This button will bring up the configuration window, in which the user can modify the data collection specifications. See the discussion of
the Config Window in this document.
2.8.4 Output Button
This button will bring up a window in which the
user can output the data to a file for later use,
print out a plot, or print out the entire screen.
When saving data, only the data channel being displayed on the plot will be saved to a file.
2.8.5 Zoom Button
This button allows the user to zoom in on the
plot by selecting two points in the plot area.
Press the Restore button to return to the normal data plot, or press the Zoom button again
to zoom in even further.
2.8.6 Channel Select Buttons
Depending on the number of channels of information that has been collected, between 1 and
3 channel select buttons will appear below the
graph, allowing the user to choose the appropriate channel for display. In the Time Domain
mode, an additional button labeled "Overlay"
will be present, to allow the user to display all
of the channels on the same plot.
2.9 Config Window
The Config Window allows the user to set up
the data collection and analysis parameters.
2.9.1 Number of Samples
This box allows the user to select the number
of samples to collect, between 16 and 8192.
Due to memory size on the CDB5461, the
maximum is 4096 samples when collecting
15
CDB5461
two channels, and 2048 samples when collecting three channels.
2.9.2 Average
When doing FFT processing, this box will determine the number of FFTs to average. FFTs
will be collected and averaged when the Collect button is pressed.
2.9.3 FFT Window
2.9.4 Histogram Bin Width
This box allows for a variable "bin width" when
plotting histograms of the collected data. Each
vertical bar in the histogram plot will contain
the number of output codes contained in this
box. Increasing this number may allow the
user to view histograms with larger input ranges.
2.9.5 Pages to Collect
This box allows the user to select the type of
windowing algorithm for FFT processing. Windowing algorithms include the Blackman,
Blackman-Harris, Hanning, 5-term Hodie, and
7-term Hodie. The 5-term Hodie and 7-term
Hodie are windowing algorithms developed at
Crystal Semiconductor.
This box determines the number of data "pages" that the microcontroller will collect before
sending data to the PC. Each page consists of
the number of samples collected, and only the
last page will be returned to the PC for processing. This function is useful at higher sampling frequencies to minimize board-level
noise at the beginning of the conversion set.
Figure 6. Time Domain Analysis
16
CDB5461
Figure 7. FFT Analysis
Figure 8. Histogram Analysis
17
CDB5461
2.9.6 Data to Collect
These six check boxes allow the user to select
the data channels that will be collected and returned to the PC for processing. Up to three
channels can be selected at once. There are
some restrictions on the speed and number of
samples to collect when selecting more than
one channel. A warning message will appear
on pressing the Collect button in the Data Collection Window if any speed limits appear to be
exceeded, but the data collection will still take
place.
2.9.7 Accept Button
When this button is pressed, the current settings will be saved, and the user will return to
the Data Collection Window.
set on the CDB5461 board.
5) Once the data has been collected, it can be
analyzed, printed, or saved to disk.
2.11 Retrieving Saved Data From a File
The CDB5461 software allows the user to
save data to a file, and retrieve it later when
needed. To load a previously saved file:
1) Pull down the Setup option and select Disk.
A file menu will appear.
2) Find the data file in the list and select it.
Press the Select button to return.
3) Go to the Data Collection Window, and
press the Collect button.
2.10 Collecting Data Sets
4) The data from the file should appear on the
screen. To select a different file, repeat the
procedure.
To collect a sample data set:
2.12 Analyzing Data
1) In the Data Collection Window, press the
Config button to bring up the Configuration
Window and view the current settings.
The evaluation software provides three types
of analysis tests: Time Domain, Frequency
Domain, and Histogram. The Time Domain
analysis processes acquired conversions to
produce a plot of Magnitude versus Conversion Sample Number. The Frequency Domain
analysis processes acquired conversions to
produce a magnitude versus frequency plot
using the Fast-Fourier transform (results up to
Fs/2 are calculated and plotted). Also, statistical noise calculations are calculated and displayed. The Histogram analysis test
processes acquired conversions to produce a
histogram plot. Statistical noise calculations
are also calculated and displayed.
2) Select the appropriate settings from the
available options (see the section on the
Configuration Window) and press the Accept button.
3) The Data Collection Window should still be
visible. Press the Collect button to begin
collecting data. A progress indicator bar
will appear at the bottom of the screen during the data collection process.
4) Data is first collected from the CS5461 and
stored in SRAM, and then transferred from
the SRAM to the PC through the RS-232
serial cable. Depending on the value of the
Cycle Count Register and the number of
samples being collected, this process may
take a long time. The process can be terminated by pressing the Stop button, but if
this is done, the user should also press Re18
2.13 Histogram Information
The following is a description of the indicators
associated with Histogram Analysis. Histograms can be plotted in the Data Collection
Window by setting the Time Domain / FFT / Histogram selector to Histogram (Figure 8).
CDB5461
2.13.1 BIN
2.13.7 VARIANCE
Displays the x-axis value of the cursor on the
Histogram.
Indicates the Variance for the current data set.
The variance is calculated using the following
formula:
2.13.2 MAGNITUDE
n-1
Σ
Displays the y-axis value of the cursor on the
Histogram.
2.13.3 MAXIMUM
Var =
Indicator for the maximum value of the collected data set.
2.13.4 MEAN
Indicator for the mean of the data sample set.
The mean is calculated using the following formula:
n-1
Σ
Mean =
(X i - Mean) 2
i=0
n
2.14 Frequency Domain Information
The following describe the indicators associated with FFT (Fast Fourier Transform) Analysis. FFT data can be plotted in the Data
Collection Window by setting the Time Domain
/ FFT / Histogram selector to FFT (Figure 7).
2.14.1 FREQUENCY
Xi
Displays the x-axis value of the cursor on the
FFT display.
i=0
n
2.14.2 MAGNITUDE
2.13.5 MINIMUM
Indicator for the minimum value of the collected data set.
2.13.6 STD. DEV.
Indicator for the Standard Deviation of the collected data set. The Standard Deviation is calculated using the following formula
n-1
Σ
StDev =
(X i - Mean) 2
Displays the y-axis value of the cursor on the
FFT display.
2.14.3 S/D
Indicator for the Signal-to-Distortion Ratio, 4
harmonics are used in the calculations (decibels).
2.14.4 S/N+D
Indicator for the Signal-to-Noise + Distortion
Ratio (decibels).
2.14.5 SNR
i=0
n
Indicator for the Signal-to-Noise Ratio, first 4
harmonics are not included (decibels).
2.14.6 S/PN
Indicator for the Signal-to-Peak Noise Ratio
(decibels).
19
CDB5461
2.14.7 # of AVG
Displays the number of FFT’s averaged in the
current display.
2.15 Time Domain Information
The following controls and indicators are associated with Time Domain Analysis. Time domain data can be plotted in the Data Collection
Window by setting the Time Domain / FFT / Histogram selector to Time Domain (Figure 6).
2.15.1 COUNT
Displays current x-position of the cursor on the
time domain display.
2.15.2 MAGNITUDE
Displays current y-position of the cursor on the
time domain display.
2.15.3 MAXIMUM
Indicator for the maximum value of the collected data set.
2.15.4 MINIMUM
Indicator for the minimum value of the collected data set.
20
Figure 9. Analog Schematic
Note: All resistor values are in Ohms
unless otherwise noted.
CDB5461
21
22
Figure 10. Digital Schematic
Note: All resistor values are in Ohms
unless otherwise noted.
CDB5461
Figure 11. Power Supply Schematic
CDB5461
23
Figure 12. Silkscreen
CDB5461
24
Figure 13. Circuit Side
CDB5461
25
Figure 14. Solder Side
CDB5461
26
CDB5461
- NOTES -
Contacting Cirrus Logic Support
For all product questions and inquiries contact a Cirrus Logic Sales Representative.
To find the one nearest to you go to www.cirrus.com
IMPORTANT NOTICE
"Preliminary" product information describes products that are in production, but for which full characterization data is not yet available. Cirrus Logic, Inc. and its
subsidiaries ("Cirrus") believe that the information contained in this document is accurate and reliable. However, the information is subject to change without notice
and is provided "AS IS" without warranty of any kind (express or implied). Customers are advised to obtain the latest version of relevant information to verify, before
placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order
acknowledgment, including those pertaining to warranty, patent infringement, and limitation of liability. No responsibility is assumed by Cirrus for the use of this information, including use of this information as the basis for manufacture or sale of any items, or for infringement of patents or other rights of third parties. This document is the property of Cirrus and by furnishing this information, Cirrus grants no license, express or implied under any patents, mask work rights, copyrights,
trademarks, trade secrets or other intellectual property rights. Cirrus owns the copyrights associated with the information contained herein and gives consent for
copies to be made of the information only for use within your organization with respect to Cirrus integrated circuits or other products of Cirrus. This consent does not
extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE ("CRITICAL APPLICATIONS"). CIRRUS PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE
IN AIRCRAFT SYSTEMS, MILITARY APPLICATIONS, PRODUCTS SURGICALLY IMPLANTED INTO THE BODY, LIFE SUPPORT PRODUCTS OR OTHER
CRITICAL APPLICATIONS (INCLUDING MEDICAL DEVICES, AIRCRAFT SYSTEMS OR COMPONENTS AND PERSONAL OR AUTOMOTIVE SAFETY OR SECURITY DEVICES). INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER'S RISK AND CIRRUS DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR PARTICULAR PURPOSE, WITH REGARD TO ANY CIRRUS PRODUCT THAT IS USED IN SUCH A MANNER. IF THE CUSTOMER OR CUSTOMER'S CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES, BY SUCH USE, TO FULLY INDEMNIFY CIRRUS, ITS OFFICERS, DIRECTORS, EMPLOYEES, DISTRIBUTORS AND OTHER AGENTS FROM ANY AND ALL LIABILITY, INCLUDING
ATTORNEYS' FEES AND COSTS, THAT MAY RESULT FROM OR ARISE IN CONNECTION WITH THESE USES.
Cirrus Logic, Cirrus, and the Cirrus Logic logo designs are trademarks of Cirrus Logic, Inc. All other brand and product names in this document may be trademarks
or service marks of their respective owners.
IBM is a trademark of International Business Machines Corporation.
Microwire, Lab Windows, and CVI are a trademark of National Semiconductor.
SPI is a trademark of Motorola, Inc.
Windows is a trademark of Microsoft Corporation.
27