CDB5460A Datasheet, PDF (8/28 Pages) Cirrus Logic – Evaluation Board and Software

CDB5460A
80C51 Mode
80C51 in Normal Operating Mode
S1-1 OPEN
S1-2 CLOSED 20 MHz Crystal
S1-3 OPEN
80C51 in Normal Operation Mode
S1-1 OPEN
S1-2 OPEN 11.059 MHz Crystal
S1-3 OPEN
80C51 in Test Mode
S1-1 OPEN
S1-2 CLOSED 20 MHz Crystal
S1-3 CLOSED
80C51 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
3
OPEN
1
2
3
OPEN
1
2
3
OPEN
Table 4. DIP Switch S1 Setting
The S1-3 switch should be set to the OPEN posi-
tion 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 80C51.
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 CS5460A operates in auto-
boot mode. When in auto-boot mode, a hardware
reset (press on S2) will cause the CS5460A to boot
up using the serial data from the serial EEPROM
on the board (U9). The EEPROM must be pro-
grammed prior to the auto-boot sequence. The EE-
PROM does come pre-programmed with a valid
boot-up sequence. This sequence programs the
CS5460A for continuous conversion mode. If volt-
age and current signals are applied to the inputs, the
CS5460A will issue pulses on the /EOUT and
/EDIR pins. Note that JP4 header must be shorted
for auto-boot to work.
When the CDB5460 Evaluation Board is sent from
the factory, the EEPROM is programmed with the
following CS5460A command/data sequence:
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 CS5460A to terminate
autoboot sequence.
The auto-boot sequence runs with no assistance
from the 8051 microcontroller. The user can verify
this by disconnecting power from the board, pull-
ing the microcontroller out of its socket, then pow-
er on again and run in auto-boot mode. See the
CS5460A data sheet for more details on auto-boot.
2. SOFTWARE
The evaluation board comes with software and an
RS-232 cable to link the evaluation board to the
PC. The evaluation software was developed with
Lab Windows/CVI^TM, a software development
package from National Instruments. The software
was designed to run under Windows 95^TM or later,
and requires about 3MB of hard drive space (2MB
for the CVI Run-Time Engine^TM, 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 development
package from National Instruments (512-794-
0100).
8