Cirrus Logic CDB5528 - Manual (Page 9)

CDB5521/22/23/24/28
DS317DB2 9
1.6 Software
The evaluation board comes with software and an
RS-232 cable to link the evaluation board to the
PC. The executable software was developed with
Lab Windows/CVI
TM and meant to run under Win-
dows TM 3.1 or later. After installing the software,
read the readme.txt file for last minute changes in
the software. Additionally, Section 2., Part II: Soft-
ware further details how to install and use the soft-
ware
1.7. Writing Your Own Interface Software
Tables 2 through 5 list the RS-232 commands used
to communicate between the PC and the microcon-
troller. To develop additional code to communi-
cate to the evaluation board via RS-232, the
following applies: to write to an internal ADC reg-
ister, choose the appropriate write command byte
(See Table 2), and transmit it LSB first. Then,
transmit the three data bytes lowest order byte (bits
7-0) first with the LSB of each byte transmitted
first. These three data bytes provide the 24-bits of
information to be written to the desired register.
To read from an internal register, choose the appro-
priate read command byte and transmit it LSB first.
Then, the microcontroller automatically acquires the
ADC’s register contents and returns the 24-bits of
information. The returned data is transmitted lowest
order byte first with the LSB of each byte transmit-
ted first.
Name Function Description
HDR1 Used to switch AIN1+ (AIN1 on
CS5528) between J1 and AGND.
HDR2 Used to switch AIN1- (AIN2 on
CS5528) between J1 and AGND.
HDR3 Does not exist.
HDR4 Used to switch the power for NBV
from the LM337, CPD, or AGND.
HDR5 Used to switch VREF+ and VREF-
pins from external J2 header to the on
board LT1019 reference.
HDR6 Used to connect an external micro-
controller.
HDR7 Used in conjunction with the self test
modes to test the UART/RS232 com-
munication link between the micro-
controller and a PC.
HDR8 Used to switch AIN2 + (AIN3 on
CS5528) between J1 and AGND.
HDR9 Used to switch AIN2- (AIN4 on
CS5528) between J1 and AGND.
HDR10 Does not exist.
HDR11 Used to switch AIN3+ (AIN5 on
CS5528) between J1 and AGND.
HDR12 Used to switch AIN3- (AIN6 on
CS5528) between J1 and AGND.
HDR13 Used to switch AIN4+ (AIN7 on
CS5528) between J1 and AGND.
HDR14 Used to switch AIN4- (AIN8 on
CS5528) between J1 and AGND.
Table 1. Header Descriptions