General Description
The MAX6955 evaluation kit (EV kit) is designed to eval-
uate the MAX6955 light-emitting diode (LED) display dri-
ver with a 2-wire interface. The EV kit board contains two
MAX6955 LED display drivers on symmetrical sides of
the board, allowing a 16-digit display using sixteen 14-
segment alphanumeric LEDs. The DB-25 connector
allows a PC's parallel (printer) port to provide the 2-wire
interface. The Windows
software provides a friendly
graphical user interface (GUI) to exercise the features of
the MAX6955 by allowing on-the-fly text and numeric
entry and access to all relevant registers. The software
includes multiple tabs for accessing the various regis-
ters and maintains a consistent format with controls on
the left side of the software's main window pertaining to
U1, located on the left side of the EV kit board. Similarly,
all the controls on the right side of the software's main
window pertain to U2, located on the right side of the EV
kit board. The EV kit board requires a 3.3VDC or 5VDC
power supply and jumpers JU1JU4 allow the user to
manually modify the device address of U1 or U2.
Order the MAX6955EVKIT for comprehensive evalua-
tion of the MAX6955 using a PC with an available paral-
lel port.
Features
o Proven PC Board Layout
o Windows 95/98/ME/NT/2000/XP-Compatible
Evaluation Software
o 2-Wire Serial Interface
o Sixteen 14-Segment Bright LEDs
o Fully Assembled and Tested
Evaluates: MAX6955
MAX6955 Evaluation Kit
________________________________________________________________ Maxim Integrated Products
1
19-2708; Rev 0; 12/02
Component List
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
DESIGNATION
QTY
DESCRIPTION
C1
1
22F 20%, 6.3V X5R ceramic
capacitor (1210)
TDK C3225X5R0J226M
C2
1
12pF 5%, 50V COG ceramic
capacitor (0603)
TDK C1608COG1H120JT
C3, C5
2
0.1F 10%, 25V X7R ceramic
capacitors (0603)
TDK C1608X7R1E104KT
C4, C6
2
1F 20%, 10V X5R ceramic
capacitors (0805)
TDK C2012X5R1A105M
D1D8
8
0.54in dual 14-segment
alphanumeric LEDs
Lumex LDD-F5406RI
Fairchild MDA6140C
D9D12
4
Zener diodes, Vz = 5.1V (3-pin
SOT23), top mark: KZ2 or Z2
Diodes Inc. BZX84C5V1
Ordering Information
PART
TEMP RANGE
IC PACKAGE
MAX6955EVKIT
0C to +70C
36 SSOP
MAX6955 EV Kit Files
PROGRAM
DESCRIPTION
INSTALL.EXE
Installs the EV kit software
MAX6955.EXE
Application program
HELPFILE.HTM
MAX6955 EV kit Helpfile
PORT95NT.EXE
SST's freeware DLPortIO driver package
UNINST.INI
Uninstalls the EV kit software
Windows is a registered trademark of Microsoft Corp.
DESIGNATION
QTY
DESCRIPTION
J1
1
Male DB-25 right-angle plug
J2, J3
2
20-pin dual-row 2 x 10 headers
JU1JU4
4
5-pin headers
N1, N2
2
N-channel MOSFETs (3-pin SOT23),
top mark: 702
Central Semiconductor 2N7002
Q1, Q2
2
Bipolar junction transistors (3-pin
SOT23), top mark: C1A
Central Semiconductor CMPT3904
R1, R5
2
100k
5% resistors (1206)
R2, R6
2
13k
5% resistors (1206)
R3, R4,
R7R10,
R13R22
16
47k
5% resistors (1206)
R11, R12
2
100k
1% resistors (1206)
U1, U2
2
MAX6955AAX (36-pin SSOP)
None
4
Shunts
Evaluates: MAX6955
MAX6955 Evaluation Kit
2
_______________________________________________________________________________________
Quick Start
Recommended Equipment
Before beginning, the following equipment is needed:
MAX6955EVKIT
A 3.3VDC or 5VDC power supply
PC with Windows 95/98/ME/NT/2000/XP
An available parallel port (female DB-25 connector
on back of PC)
A standard 25-pin, straight-through, male-to-female
cable to connect the PC's parallel port to the
MAX6955 EV kit board
Procedure
1) Connect a cable from the PC's parallel port to the
MAX6955 EV kit board. Use a 25-pin, straight-
through, female-to-male cable.
2) Install the supplied CD into the CD drive of your PC
and run INSTALL.EXE. When the installer window
shows up on the screen, press the INSTALL button.
The MAX6955 program files are copied and icons
are created in the Programs section within the Start
menu. When you see the self-extracting DLPortIO
driver install window appear on the screen, press
the Yes button. This automatically unpacks the com-
pressed files and runs the DLPortIO driver installer.
If using Windows NT, 2000, or XP, you must have
administrator privileges on your PC. If you do not,
then contact your system administrator to allow
installation. You need to restart your PC after
installing the DLPortIO driver.
3) Connect a 3.3VDC or 5VDC power supply between
the VCC and GND pads on the MAX6955 EV kit
board.
4) Start the MAX6955 EV kit program by double click-
ing its icon located in the Programs section within
the Start menu.
5) The program automatically detects the MAX6955 EV
kit board and displays 2-wire Hardware Detected in
a green font.
6) The MAX6955 EV kit board and MAX6955 EV kit soft-
ware should automatically display MAX6955 EVKIT.
Software Description
The EV kit software's main window, shown in Figure 1,
allows on-the-fly text and numeric entry and also allows
access to all the relevant registers for easy configuration.
The controls on the left side of the software's main win-
dow control U1 and similarly, the controls on the right
side of the software's main window control U2. Each reg-
ister has its own tab in the order of the MAX6955's
address map. A 2-wire operation field is present at the
very bottom of the software's main window, which shows
the results of the last 2-wire operation.
Alphanumeric Entry for U1
In the upper left-hand corner of the software's main
window is the Alphanumeric Entry for U1 group box.
This group box has five main controls:
Plane group box
U1 Address (write) combo box
U1 Address (read) combo box
Alphanumeric entry field
Decimal Point checkbox and individual decimal
point checkboxes
The first control is the Plane group box, which allows
the user to select which plane to write to. The radio but-
ton choices in the Plane group box are P0 and P1, P0,
and P1. It is important to note that once one of these
plane radio buttons is selected, the software automati-
cally takes the text or numbers that exist in the
Alphanumeric Entry field and writes them to the display.
The second and third controls are the U1 Address
(write) and the U1 Address (read) combo boxes.
These device-address combo boxes default to 0xCA
for write and 0xCB for read. If you modify the default
device address, change the jumper settings on JU1
and JU2 on the MAX6955 EV kit board. If the default
address settings are changed on the board, the user
must also manually select the correct device address
Component Suppliers
SUPPLIER
PHONE
WEBSITE
Central
Semiconductor
631-435-1110
www.centralsemi.com
Diodes Inc.
805-446-4800
www.diodes.com
Fairchild
Semiconductor
888-522-5372
www.fairchildsemi.com
Lumex, Inc.
800-278-5666
www.lumex.com
Scientific Software
Tools, Inc.
610-891-1640
www.sstnet.com
TDK
847-803-6100
w w w .com p onent.td k.com
in the U1 Address (write) and the U1 Address (read)
combo boxes. Table 1 lists the device address selec-
tion for the various JU1 and JU2 jumper settings.
The fourth control is the Alphanumeric Entry field,
which displays MAX6955 at the start of the program.
The user may type letters, numbers, apostrophes, com-
mas, or even spaces in the Alphanumeric Entry field
using the computer's keyboard. The Alphanumeric
Entry field also supports standard word processing fea-
tures like highlighting, insert, and delete. Anytime an
invalid character is typed into the Alphanumeric Entry
field, such as an @, a character error message box
pops up, indicating an invalid character was typed.
Anytime a valid character is typed into the Alpha-
numeric Entry field, the software automatically writes it
to the corresponding digit on the display.
The last control type within the Alphanumeric Entry
for U1 group box is the Decimal Point checkbox and
the individual decimal point checkboxes. When the
Decimal Point checkbox is checked, all of the individ-
ual decimal point checkboxes become visible. When
the Decimal Point checkbox is unchecked, all of the
individual decimal point checkboxes are hidden.
Checking one of the individual decimal point check-
boxes automatically lights up the corresponding deci-
mal point on the board.
Evaluates: MAX6955
MAX6955 Evaluation Kit
_______________________________________________________________________________________
3
Figure 1. MAX6955 EV Kit Software's Main Window
Evaluates: MAX6955
Alphanumeric Entry for U2
The Alphanumeric Entry for U2 group box is in the
upper right-hand corner of the software's main window.
This group box has five main controls:
Plane group box
U2 Address (write) combo box
U2 Address (read) combo box
Alphanumeric Entry Field
Decimal Point checkbox and individual decimal
point checkboxes
The first control is the Plane group box, which allows
the user to select which plane to write to. The radio but-
ton choices in the Plane group box are P0 and P1, P0,
and P1. It is important to note that once one of these
plane radio buttons is selected, the software automati-
cally takes the text or numbers that exist in the
Alphanumeric Entry field and writes them to the display.
The second and third controls are the U2 Address
(write) and the U2 Address (read) combo boxes.
These device address combo boxes default to 0xC0 for
write and 0xC1 for read. If you modify the default
device address, change the jumper settings on JU3
and JU4 on the MAX6955 EV kit board. If the default
address settings are changed on the board, the user
must also manually select the correct device address in
the U2 Address (write) and the U2 Address (read)
combo boxes. Table 2 lists the device address selec-
tion for the various JU3 and JU4 jumper settings.
The fourth control is the Alphanumeric Entry field, which
displays EVKIT at the start of the program. The user
may type letters, numbers, apostrophes, commas, or
even spaces in the Alphanumeric Entry field using the
computer's keyboard. The Alphanumeric Entry field
also supports standard word processing features like
highlighting, insert, and delete. Anytime an invalid char-
acter is typed into the Alphanumeric Entry field, such
as an @, a character error message box pops up, indi-
cating an invalid character was typed. Anytime a valid
character is typed into the Alphanumeric Entry field, the
software automatically writes it to the corresponding
digit on the display.
The last control type within the Alphanumeric Entry
for U2 group box is the Decimal Point checkbox and
the individual decimal point checkboxes. When the
Decimal Point checkbox is checked, all of the individ-
ual decimal point checkboxes become visible. When
the Decimal Point checkbox is unchecked, all of the
individual decimal point checkboxes are hidden.
Checking one of the individual decimal point checkbox-
es automatically lights up the corresponding decimal
point on the board.
Register Tabs
The MAX6955 EV kit software has 43 register tabs for
both U1 and U2, giving access to 86 unique registers.
Any register tab can be selected by a mouse click
when visible and not all register tabs can be visible at
once. Scroll through the register tabs using the left and
right scroll arrows located on the right-hand side of the
software's main window. The order of the register tabs
corresponds to the same order of the MAX6955's
address map. Refer to the MAX6955 IC data sheet for
details on the address map and a complete description
of each register.
Keyboard Navigation
When you type on the keyboard, the system must know
which control should receive the keys. Press the tab
key to move the keyboard's focus from one control to
the next. The focused control is indicated by a dotted
outline. Shift + tab moves the focus to the previously
focused control. Buttons respond to the keyboard's
space bar. Some controls respond to the keyboard's
up and down arrow keys. Activate the program's menu
bar by pressing the F10 key, then press the letter of the
menu item you want. Most menu items have one letter
underlined, indicating their shortcut key.
Hardware Description
The MAX6955 EV kit board is designed symmetrically
so that the left side of the board pertains to U1 and the
right side of the board pertains to U2. Thus, the first
eight digits are driven by U1 and the last eight digits
are driven by U2. An OSC pad for U1 is provided for
external clock operation and an OSC_OUT pad for U2
is also provided for cascading additional MAX6955
devices. The DB-25 connector and associated circuitry
are only needed for obtaining the 2-wire interface from
the PC's parallel port and are not needed in typical
applications. Connect the DB-25 connector, J1, to the
PC's parallel port using a 25-pin straight-through,
female-to-male cable. Four jumpers are on the EV kit
board to modify the device address for U1 and U2. The
two dual-row 20-pin headers, J2 and J3, are used for
the I/O expander and keyscan features of U1 and U2,
respectively.
Device Address Jumpers JU1JU4
The MAX6955 EV kit board contains four jumpers in the
top right-hand corner of the board. Jumpers JU1 and
MAX6955 Evaluation Kit
4
_______________________________________________________________________________________
JU2 select the device address for U1 and jumpers JU3
and JU4 select the device address for U2.
Table
1 lists
the device address selection for the various JU1 and
JU2 jumper settings.
Table
2 lists the device address
selection for the various JU3 and JU4 jumper settings.
Before changing the default device address for U1 or
U2, read the Alphanumeric Entry for U1 and
Alphanumeric Entry for U2 sections pertaining to
required modifications for the Address (write) and
Address (read) combo boxes.
OSC and OSC_OUT Pads
An OSC pad for U1 is provided for external clock oper-
ation and an OSC_OUT pad for U2 is also provided for
cascading additional MAX6955 devices. When the
OSC pad is unconnected, the internal oscillator of U1
drives both U1 and U2 because OSC_OUT of U1 is
directly connected to OSC of U2 with a trace on the
board. It is also possible to drive the OSC pad of U1
with an external clock between 1MHz to 8MHz.
SCL, SDA, and GND Pads
The MAX6955 EV kit utilizes the PC's parallel port to
generate a 2-wire interface for easy evaluation.
Customers who wish to evaluate U1 and U2 using their
own 2-wire interface must remove the parallel port
cable from the board and attach the new 2-wire inter-
face to the SCL, SDA, and GND pads located on the
upper left-hand side of the MAX6955 EV kit board. The
SCL, SDA, and GND pads are also useful for probing
the 2-wire waveforms with a digital oscilloscope or logic
analyzer.
Evaluates: MAX6955
MAX6955 Evaluation Kit
_______________________________________________________________________________________
5
Table 1. U1 Address Selection for
Jumpers JU1 and JU2
JUMPER POSITION
DEVICE ADDRESS
JU1
JU2
(Write)
(Read)
1-2
1-2
0xDE
0xDF
1-3
1-2
0xDA
0xDB
1-4
1-2
0xDC
0xDD
1-5
1-2
0xD8
0xD9
1-2
1-3
0xCE
0xCF
1-3*
1-3*
0xCA*
0xCB*
1-4
1-3
0xCC
0xCD
1-5
1-3
0xC8
0xC9
1-2
1-4
0xD6
0xD7
1-3
1-4
0xD2
0xD3
1-4
1-4
0xD4
0xD5
1-5
1-4
0xD0
0xD1
1-2
1-5
0xC6
0xC7
1-3
1-5
0xC2
0xC3
1-4
1-5
0xC4
0xC5
1-5
1-5
0xC0
0xC1
*Default for U1.
Table 2. U2 Address Selection for
Jumpers JU3 and JU4
JUMPER POSITION
DEVICE ADDRESS
JU3
JU4
(Write)
(Read)
1-2
1-2
0xDE
0xDF
1-3
1-2
0xDA
0xDB
1-4
1-2
0xDC
0xDD
1-5
1-2
0xD8
0xD9
1-2
1-3
0xCE
0xCF
1-3
1-3
0xCA
0xCB
1-4
1-3
0xCC
0xCD
1-5
1-3
0xC8
0xC9
1-2
1-4
0xD6
0xD7
1-3
1-4
0xD2
0xD3
1-4
1-4
0xD4
0xD5
1-5
1-4
0xD0
0xD1
1-2
1-5
0xC6
0xC7
1-3
1-5
0xC2
0xC3
1-4
1-5
0xC4
0xC5
1-5*
1-5*
0xC0*
0xC1*
*Default for U2.
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