MAX155EVKIT-DIP Maxim Integrated, MAX155EVKIT-DIP Datasheet - Page 4

• Manufacturer Part Number: MAX155EVKIT-DIP
• Description: Data Conversion IC Development Tools Evaluation Kit for the MAX155
• Manufacturer: Maxim Integrated
• Series: MAX155, MAX156r

However, an 8-bit device like the MAX155 does not
require data-bus isolation in many applications.
Precautions were also taken to avoid digital noise in the
ground and +5V supply lines to the MAX155. On the
board layout, both traces to the MAX155 are wide
traces that return directly to the regulator output. In
general, supply lines to ADC devices should avoid the
current spikes found on supply lines to digital circuits.
The software driver for the MAX155 EV kit is divided
into two elements. One is the ROM code written for the
80C32 controller. The other is a program written in C
that runs on an IBM-compatible personal computer.
The disk supplied with the kit contains the instruction
manuals and source code for each program.
The disk also holds two other important files. The first is
a README file describing any changes to the hardware
or software. Be sure to read the file as soon as possi-
ble. The other file is an update registration form. Be
sure to fill out and return the update form for future
package updates.
The 80C32 code was written using the AVOCET 8051
Assembler. The output code is stored in a 27C64
EPROM placed on the MAX155 EV kit board, The
EPROM code initializes the 80C32 after a reset and
establishes communications over the RS-232 serial link.
After reset, the program continuously transmits an
A5(hex) character until the proper response is
received. It then waits for the command for a conver-
sion or other function. The list of available commands is
in the disk documentation.
The MAX155EV.exe program runs on an IBM-compatible
computer. It displays the EV kit status and conversion
results. The program establishes the communications
link with the EV kit board. The status flag in the lower
right corner of the screen indicates READY when com-
munication has been established.
A menu of available commands appears at the bottom
of the screen during operation. For a detailed explana-
tion of the commands, read the SOFTWARE.doc file
found on the disk.
For information on program installation, see the section
titled Loading the Software.
MAX155 Evaluation Kit
4
_______________________________________________________________________________________
Personal Computer Software
Software Architecture
ROM Firmware
The typical EV kit board consumes 80mA from a 6V to
12V external power supply. The supply can be an
adjustable laboratory supply, a 9V alkaline battery, or
an isolated wall-mounted DC power supply.
J1 on the printed circuit board is the MANUAL RESET
jumper. These pins are connected to the MAX696's
LL
1.30V, a reset pulse is generated. To manually reset the
board, briefly place a short across the pins and
remove. After reset, the board attempts to establish
communications with the host system.
These pins should never be connected to other parts of
the circuit.
J2 is the watchdog-enable jumper (WDI ENABLE). If
enabled, the watchdog function resets the µP if it fails
to toggle the watchdog input once every second. A
shunt is normally installed across the jumper pins to
enable the watchdog. It can be removed (before
power-up) to avoid unwanted resets while debugging
80C32 software. See the MAX696 data sheet for more
information.
A 74HCT161 binary counter divides the 10MHz clock
signal. This device's four outputs are selectable with
J10–J13. The boards are built with a trace across J10
Table 2. MAX155 EV Software Command
List
IN
input and ground. If the LL
0–7
CR
D
U
H
C
S
B
R
E
Application Information
Select a channel
Set single-ended mode
Set differential mode
Set unipolar mode
Set bipolar mode
Set hexadecimal output format
Collect sample and save in RAM
Examine the RAM contents
Continuous conversion
Single conversion
Power Requirements
IN
Jumper Options
input is lower than
Watchdog Enable
Clock Selection
Manual Reset