CDB5461 Datasheet, PDF (7/27 Pages) Cirrus Logic – Evaluation Board and Software

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
123
OPEN
123
OPEN
123
OPEN
123
OPEN
123
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 op-
tions available, 11.059 MHz and 20 MHz. If
S1-2 is OPEN the 11.059 MHz crystal is se-
lected, and when S1-2 is CLOSED the 20 MHz
crystal is selected.
If S1-1 is closed, the CS5461 operates in auto-
boot mode. When in auto-boot mode, a hard-
ware 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
inputs, the CS5461 will issue pulses on the
/EOUT and /EDIR pins. The J24 header must
be shorted for auto-boot to work.
When the CDB5461 Evaluation Board is sent
from the factory, the EEPROM is programmed
with the following CS5461 command/data se-
quence:
40 00 00 61
4C 10 00 00
E8
;In configuration Register, turn
high- pass filters on, set K = 1.
;Set Pulse Rate Register to
32768 Hz.
;Start continuous conversions.
78 00 01 00 ;Write stop bit to CS5461 to termi-
nate autoboot sequence.
The auto-boot sequence runs with no assis-
tance 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 auto-
boot 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 devel-
oped with Lab Windows^®/CVI^®, a software de-
velopment 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 eval-
uation software). After installing the software,
read the readme.txt file for any last minute up-
dates or changes. More sophisticated analysis
software can be developed by purchasing the
LabWindows^® development package from Na-
tional Instruments.
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