Axiom DEMO9S12XDT512 User manual

DOC-0350-010, REV E
Email: www.axman.com
Support: [email protected]
DEMO9S12XDT512
DEVELOPMENT BOARD FOR FREESCALE
MC9S12XDT512
USER GUIDE

DEMO9S12XDT512 JULY 18, 2008
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CONTENTS
CAUTIONARY NOTES ..............................................................................................................4
TERMINOLOGY.........................................................................................................................4
FEATURES................................................................................................................................5
REFERENCES...........................................................................................................................6
GETTING STARTED..................................................................................................................6
OPERATING MODES................................................................................................................6
RUN MODE........................................................................................................................... 7
DEBUG MODE......................................................................................................................7
MEMORY MAP ..........................................................................................................................8
SOFTWARE DEVELOPMENT...................................................................................................8
DEVELOPMENT SUPPORT......................................................................................................9
INTEGRATED BDM .............................................................................................................. 9
BDM_PORT HEADER........................................................................................................... 9
POWER....................................................................................................................................10
POWER SELECT................................................................................................................ 10
PWR_SEL........................................................................................................................10
VX_EN..............................................................................................................................11
RESET SWITCH ......................................................................................................................11
LOW VOLTAGE RESET..........................................................................................................11
TIMING.....................................................................................................................................11
COMMUNICATIONS................................................................................................................12
RS-232 ................................................................................................................................ 12
COM CONNECTOR.........................................................................................................13
LIN COMMUNICATIONS..................................................................................................... 13
LIN_EN.............................................................................................................................13
CAN COMMUNICATIONS................................................................................................... 14
MODE.......................................................................................................................................14
VRH/VRL..................................................................................................................................14
USER I/O..................................................................................................................................15
SWITCHES ......................................................................................................................15
LED’S...............................................................................................................................15
POT..................................................................................................................................16
LIGHT SENSOR...............................................................................................................16
USER SIGNALS.................................................................................................................. 16
USER ENABLE ................................................................................................................... 16
MCU I/O PORT.........................................................................................................................17
APPENDIX A............................................................................................................................19

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TOP SILKSCREEN ............................................................................................................. 19
TABLE OF FIGURES
Figure 1: USB_SPEED Option Header ..................................................................................................................... 9
Figure 2: BDM_PORT ............................................................................................................................................... 9
Figure 3: PWR_SEL Option Header........................................................................................................................ 10
Figure 4. VX_EN Option Header............................................................................................................................ 11
Figure 5. CLK_SEL Option Header........................................................................................................................ 12
Figure 6: COM Connector ....................................................................................................................................... 13
Figure 7: LIN Connector.......................................................................................................................................... 13
Figure 8. LIN_EN Option Header ........................................................................................................................... 13
Figure 9. CAN_PORT Connector........................................................................................................................... 14
Figure 10. MODE Option Header........................................................................................................................... 14
Figure 11: MCU I/O PORT – J1............................................................................................................................... 17
Figure 12. MCU I/O PORT – J2.............................................................................................................................. 18
TABLE OF TABLES
Table 1: Run Mode Setup.......................................................................................................................................... 7
Table 2: BDM Mode Setup........................................................................................................................................ 8
Table 3: Memory Map................................................................................................................................................ 8
Table 4: COM Connections..................................................................................................................................... 12
Table 5: ATD Reference Voltage............................................................................................................................. 15
Table 6: User I/O ..................................................................................................................................................... 16
Table 7: USER Option Header................................................................................................................................ 17
Revision History
Date Rev Comments
March 24, 2005 A Initial Release
March 31, 2005 B Added corrections noted in “Out-of-Box” review. Removed reference
to serial cable, Demo program and Troubleshooting section.
May 9, 2005 C Removed Motorola reference in document
August 15, 2005 D Corrected SCI0 and SCI1 assignments in COM section.
July 18, 2008 E Updated cover page, removed Appendix B, minor text and formatting
corrections

DEMO9S12XDT512 JULY 18, 2008
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CAUTIONARY NOTES
1) Electrostatic Discharge (ESD) prevention measures should be used when handling this
product. ESD damage is not a warranty repair item.
2) Axiom Manufacturing does not assume any liability arising out of the application or use of
any product or circuit described herein; neither does it convey any license under patent
rights or the rights of others.
3) EMC Information on the DEMO9S12XDT512 board:
a) This product as shipped from the factory with associated power supplies and cables,
has been verified to meet with requirements of CE and the FCC as a CLASS A product.
b) This product is designed and intended for use as a development platform for hardware
or software in an educational or professional laboratory.
c) In a domestic environment, this product may cause radio interference in which case the
user may be required to take adequate prevention measures.
d) Attaching additional wiring to this product or modifying the products operation from the
factory default as shipped may effect its performance and cause interference with
nearby electronic equipment. If such interference is detected, suitable mitigating meas-
ures should be taken.
TERMINOLOGY
This development module utilizes option select jumpers to configure default board operation.
Terminology for application of the option jumpers is as follows:
Jumper – a plastic shunt that connects 2 terminals electrically
Jumper on, in, or installed - jumper is installed such that 2 pins are connected together
Jumper off, out, or idle - jumper is installed on 1 pin only. It is recommended that jumpers
be idled by installing on 1 pin so they will not be lost.
Cut-Trace – a circuit trace connection between component pads. The circuit trace may be
cut using a knife to break the default connection. To reconnect the circuit, simply install a
suitably sized 0-ohm resistor or attach a wire across the pads.
Signal names followed by an asterisk (*) denote active-low signals.

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FEATURES
The DEMO9S12XDT512 is an evaluation or demonstration board for the Freescale
MC9S12XDT512 MCU. Development of applications is quick and easy with the integrated
USB-Multilink BDM, sample software tools, and examples. A standard BDM debug port is also
provided, but not populated, to allow use of an external BDM pod. Two 40-pin connectors al-
low the demonstration board to be connected to an expanded evaluation environment or to
external test equipment.
Features:
♦MC9S12XDT512 MCU, 80 LQFP
♦X-GATE Co-Processor
♦512 KB Flash EEPROM
♦4KB EEPROM
♦32 KB SRAM
♦59 GPIO lines
♦Enhanced Capture Timer/PWM
♦SCI and SPI Communications Ports
♦Key Wake-up Port
♦Single Wire BDM Interface
♦CAN 2.0 A/B Module
♦Analog to Digital Converter
♦80 MHz Bus Operation using internal PLL
♦Integrated USB-Multilink BDM for DEBUG access
♦Optional power from USB bus through USB-Multilink BDM
♦Optional on-board, regulated +5V power supply for stand-
alone operation
♦Optional power through MCU I/O connector
♦Power Input Selection
♦USB Connector
♦2.0mm barrel connector
♦MCU I/O Connector
♦On-Chip Voltage Regulator with low-voltage detect (LVD)
and low-voltage interrupt (LVI)
♦4 MHz crystal oscillator in low-power Pierce configuration
default
♦Optional full-power Pierce configuration (requires installation of
R9)
♦Socket for optional full- or half-can clock oscillator
♦RS-232 serial port w/ DB9 connector
♦8-Ch, 10-bit, ATD with external trigger capability
♦16-Ch, 10-bit, ATD with external trigger capability
♦Enhanced Capture Timer with IC, OC, PWM and Pulse Accumulate capabilities
♦User Components Provided
♦4 Position DIP Switch
♦3 Push Button Switches: 2 User, RESET
♦7 LED Indicators: 4 User, 2 USB, +5V
♦Jumpers
♦Enable/Disable User functions
♦PWR_SEL
♦VX_EN
♦LIN_EN
♦CLK_SEL

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♦USB_SPEED
♦Connectors
♦Two 40-pin, pass-thru type, MCU I/O Connectors, providing access to most MCU IO signals
♦2.0mm barrel connector power input
♦USB Type-B connector
♦6-pin BDM interface connector (not installed)
♦DB9 COM connector
♦2 4-pos LIN connectors
♦3-pos CAN connector
♦Supplied with LIN Cable, USB Cable, Documentation (CD), and Manual
Specifications:
Module Size 4.0” x 3.1”
Power Input: +6VDC to +18VDC
NOTE: LIN functionality supported when powered from PWR connector only
REFERENCES
Reference documents are provided on the support CD in Acrobat Reader format.
DEMO9S12XDT512_UG_A.pdf DEMO9S12XDT512 User Guide (this document)
DEMO9S12XDT512QSG.pdf DEMO9S12XDT512 Quick Start Guide
DEMO9S12XDT512 _SCH_D.pdf DEMO9S12XDT512 Schematic Rev. D
9S12XDP512V2_ZIP.zip DEMO9S12XDT512 Device User Guide
AN2546.pdf S12X Load RAM and Execute (LRAE) Program Appli-
cation Note
AN2615.pdf HCS12 and S12X Family Compatibility
AN2685.pdf How to Configure and Use the XGATE on S12X De-
vices
AN2708.pdf An Introduction to the External Bus Interface on the
HCS12X
GETTING STARTED
To get started quickly, please refer to the DEMO9S12XDT512 Quick Start Guide. This quick
start will show the user how to connect the board to the PC, run a LED test program, install the
correct version of CodeWarrior Development Studio, and load an Analog to Digital (ATD) test
program using CodeWarrior.
OPERATING MODES
The DEMO9S12XDT512 board operates in two operating modes: Run Mode, or Debug Mode.
Run Mode allows user application operation from Power-On or Reset. Debug Mode supports
the development and debug of applications. See the related sections below for quickly starting
the board in the desired operation mode.
The board has been preloaded with a demonstration program. The demo program operates in

DEMO9S12XDT512 JULY 18, 2008
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the Run Mode. The +5V LED will light when power is applied to the board.
RUN MODE
Run mode allows user application to function when power is applied to the board. Use the
following settings to configure the DEMO9S12XDT512 board for RUN Mode to get started
quickly.
1. Connect auxiliary equipment to board as required by application.
2. Configure the board option jumpers for run mode.
Table 1: Run Mode Setup
PWR_SEL Pin1 – Pin2 (VB)
CLK_SEL Pin1 – Pin2 (Y1)
VX_EN Off
USER As Required
LIN_EN As Required
USB_SPEED Pin1 – Pin2 (HIGH)
NOTE: See Power section below to configure power input from PWR connector or from J1 connector.
3. Apply power to the board.
4. The programmed application will begin to execute.
Debug Mode
Debug Mode supports application development and debug. Debug mode is available to the
user through the integrated USB-Multilink BDM or the by using an external HCS12 BDM cable.
Use of the integrated USB-Multilink BDM requires only a host PC with an available USB port
and an A/B type USB cable. A 6-pin BDM interface header (BDM_PORT) supports the use of
an external HCS12 BDM cable. The BDM_PORT header is not installed in default configura-
tion. The steps below describe using the integrated USB-Multilink BDM.
1. Connect auxiliary equipment to board as required by application.
2. Install and launch P&E PKG12Z tool set, CodeWarrior Development Studio, or other soft-
ware capable of communicating with the HCS12 MCU.
3. Configure the board option jumpers for DEBUG mode.

DEMO9S12XDT512 JULY 18, 2008
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Table 2: BDM Mode Setup
PWR_SEL Pin1 – Pin2 (VB)
CLK_SEL Pin1 – Pin2 (Y1)
VX_EN Off
USER As Required
LIN_EN As Required
USB_SPEED Pin1 – Pin2 (HIGH)
NOTE: Refer to the Development Support section below for details on using an external HCS12 BDM cable.
4. Connect the supplied USB cable between an available USB port on the host PC and the
USB connector on the board.
5. Hosting development software will establish DEBUG communication.
6. If the P&E Connection Assistant appears, ensure the following settings
Interface: USB HCS08/HCS12 MULTILINK – USB PORT
Port: USB1 : USB-ML-12 REF : DEMO9S12XDT512
CPU: HC12/HCS12 - Autodetect Device Type
MEMORY MAP
The table below shows the default memory map for the MC9S12XDP512 immediately out of
reset.
Table 3: Memory Map
$0000 -
$07FF REGISTERS 2 KB
$0800 -
$0FFF EEPROM 4 KB 4 – 1Kb pages between 0x800 –
0xBFF
$1000 -
$3FFF RAM 12 KB 5 – 4Kb pages between 0x1000 –
0x1FFF
$4000 -
$7FFF FIXED FLASH 16 KB 1K, 2K, 4K, 8K Protected Boot
Sector
$8000 -
$BFFF FLASH EEPROM
PAGE WINDOW 16 KB 32 – 16Kb pages
$C000 -
$EFFF FIXED FLASH 16 KB 2K, 4K, 8K, 16K Protected Boot
Sector
$FF00 -
$FFFF Vectors
BDM (if active) 255 bits
SOFTWARE DEVELOPMENT
Software development will require the use of an assembler or compiler supporting the HCS12
instruction set and a host PC operating a debug interface. The assembler or compiler must
also support the HC(S)12 X-Gate instruction set. CodeWarrior Development Studio and Axiom
IDE for Windows for Debugging and Flash programming are supplied with this board.

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DEVELOPMENT SUPPORT
Application development and debug for the target MC9S12XDT512 is supported through the
BDM interface. The BDM interface consists of an integrated USB-Multilink BDM and a 6-pin
interface header (BDM_PORT) to connect a HCS12 BDM cable.
Integrated BDM
The DEMO9S12XDT512 board features an integrated USB-Multilink BDM from P&E Micro-
computer Systems. The integrated USB-Multilink BDM supports application development and
debugging via background debug mode. All necessary signals are provided by the integrated
USB-Multilink BDM. A USB, type B, connector provides connection from the target board to
the host PC.
The integrated USB-Multilink BDM provides +5V power and ground to target board eliminating
the need to power the board externally. Power from the USB-Multilink BDM is derived from the
USB bus; therefore, total current consumption for the target board, and connected circuitry,
must not exceed 500mA. This current limit describes the current supplied by the USB cable to
the BDM, target board, and any connected circuitry. Excessive current drain will violate the
USB specification. Damage to the host PC USB hub or the target board may result.
The communications speed over the USB bus is controlled by the USB_SPEED header.
When shipped from the factory, the DEMO9S12XDT512 is configured for high-speed opera-
tion. If the user encounters a communication failure, USB communication speed may be re-
duced by setting this option jumper to Full.
Figure 1: USB_SPEED Option Header
USB_SPEED Configuration:
HIGH 123FULL 1 – 2: Selects USB High-speed communications
2 – 3: Selects USB Full-speed communications
CAUTION: Do not allow total current drain to exceed 500mA when powered from the
USB-Multilink BDM .
BDM_PORT Header
A compatible HCS12 BDM cable can also attach to the 6-pin BDM interface header
(BDM_PORT). This header is not installed in default configuration. The figure below shows
the pin-out for the DEBUG header
Figure 2: BDM_PORT
MODC/BKGD 1 2 GND
3 4 RESET*
5 6 VDD
See the HC12 Reference Manual for
complete DEBUG documentation
NOTE: This header is not installed in default configuration.

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POWER
The DEMO9S12XDT512 is designed to be powered through the USB-Multilink BDM during
application development. A 2.0mm barrel connector has been applied to support stand-alone
operation and to support LIN functionality. The board may also be powered through connector
J1. This connection may also be used to supply power from the board to external circuitry.
During application development, the board should be configured to draw power from the USB-
Multilink BDM. The barrel connector may be used to support LIN functionality during applica-
tion development. The barrel connector input is also used to provide power during stand-alone
operation.
POWER SELECT
Power may be applied to the board through the integrated USB-Multilink BDM circuitry, a
2.0mm barrel connector, or through connector J1. Power selection is achieved using 2 selec-
tion headers: PWR_SEL option header and the VX_EN option header.
PWR_SEL
The PWR_SEL option header selects power input either from the integrated USB-Multilink
BDM circuitry or from the on-board voltage regulator. The figure below details the PWR_SEL
header connections.
Figure 3: PWR_SEL Option Header
VB PW
123
PWR_SEL
CONFIGURATION
1 – 2: Selects power input from USB-ML12
2 – 3: Selects power input from on-board regulator or J1
NOTE: Set PWR_SEL jumper to VB during application development. Use barrel connector in-
put (PWR) to support LIN functionality as needed.
Power from the integrated BDM is drawn from the USB bus and is limited to 500 mA. This cur-
rent limit describes the total current supplied over the USB cable to the BDM, target board and
any connected circuitry. Current drain in excess of 500 mA will violate the USB specification
and may result in damage to the host PC or the target board. At minimum, excessive current
drain will cause the host PC to spontaneously reboot. Power is provided through the inte-
grated BDM to the target board.
The on-board voltage regulator (VR1) accepts power input through a 2.0mm barrel connector
(PWR). Input voltage may range from +6V to +18V. The voltage regulator (VR1) provides a
+5V fixed output limited to 250mA. Over-temperature and over-current limit built into the volt-
age regulator provides protection from excessive stress. Consider the maximum output cur-
rent limit of VR1 when attempting to power off-board circuitry through connector J1.

DEMO9S12XDT512 JULY 18, 2008
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VX_EN
The VX_EN option header is a 2-pin jumper that connects/disconnects input J1-1 directly to
the target board +5V voltage rail. J1-3 is directly connected to the ground plane. Use of this
feature requires a regulated +5V input power source. This power input is decoupled to mini-
mize noise input but is not regulated. Care should be exercised when using this feature; no
protection is applied on this input and damage to the target board may result if over-driven.
Also, do not attempt to power the target board through this connector while also applying
power through the USB-Multilink BDM or the PWR connector; damage to the board may result.
Power may also be sourced to off-board circuitry through the J1 connector. Current output to
external circuitry is limited by the current supplied from the USB bus or the on-board regulator.
Excessive current drain may damage the target board, the host PC USB hub, or the on-board
regulator. The figure below details the VX_EN header connections.
Figure 4. VX_EN Option Header
ON OFF
1 2 Enabled Disabled
VX_EN
CAUTION: Do not exceed available current supply from USB-Multilink BDM or on-board regu-
lator, when sourcing power through connector J1 to external circuitry.
RESET SWITCH
The RESET switch provides a method to apply an asynchronous RESET to the MCU. The
RESET switch is connected directly to the RESET* input on the MCU. Pressing the RESET
switch applies a low voltage level to the RESET* input. A pull-up bias resistor allows normal
MCU operation. Shunt capacitance ensures an adequate input pulse width.
LOW VOLTAGE RESET
The MC9S12XDT512 utilizes an internal Low Voltage Reset (LVR) circuit. The LVR holds the
MCU in reset until applied voltage reaches an appropriate level. The LVR also protect against
under-voltage conditions. Consult the MC9S12XDT512 reference manual for details LVR op-
eration.
TIMING
Default timing configuration for the DEMO9S12XDT512 is a low-power, low-noise Pierce os-
cillator. In this mode, oscillator swing is typically 1VPP. The Pierce oscillator input is supplied
by a 4 MHz, fundamental frequency, crystal oscillator at location Y1. The crystal oscillator ex-
hibits a frequency tolerance of 30ppm. An optional socket at X1 is also provided to support
alternate MCU input frequencies. This socket supports full- and half-size can clock oscillators.

DEMO9S12XDT512 JULY 18, 2008
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The XCLKS* signal allows the user to configure the timing input as a full-power Pierce oscilla-
tor. Full power Pierce mode requires installing an 0805 size, 1M ohm resistor at location R9.
The XCLKS* jumper should be disabled when using an optional clock oscillator.
The CLK_SEL option header selects the on-board XTAL oscillator, the optional CLOCK oscil-
lator socket, or configures the MCU to accept a full-power Pierce Oscillator input as timing
source for the MCU. The figure below shows settings for CLK_SEL option header.
Figure 5. CLK_SEL Option Header
CLK_SEL
11 2 Select XTAL oscillator Y1 output (default)
3 4 Select Clock oscillator X1 output
5 6 Enable full-power Pierce input
3
NOTE: When applying the Clock Oscillator (X1), do not enable XCLKS*
NOTE: Enabling the full-power Pierce oscillator requires installing a 1M ohm resistor at location R9.
CAUTION: On revision D or earlier boards, only a 3.0V output clock oscillator may be used. Using
a clock with 5.0V output will damage the MCU.
COMMUNICATIONS
The DEMO9S12XDT512 board provides two Enhanced Serial Communications Interface
(ESCI) ports. SCI0 is applied to RS-232 serial communications (COM) on the target board.
SCI1 is applied to LIN communications on the target board. RS-232 communications are sup-
ported through a DB9 connector. LIN communications are supported through a pair of 4-pin
Molex connectors.
RS-232
An RS-232 translator provides RS-232 to TTL/CMOS logic level translation on the COM con-
nector. The COM connector is a 9-pin Dsub, right-angle connector. A ferrite bead on shield
ground provides conducted immunity protection. Communication signals TXD and RXD are
routed from the transceiver to the MCU. Hardware flow control signals RTS and CTS are
available on the logic side of U3. These signals are routed to vias located near the transceiver
(U3). RTS has been biased properly to support 2-wire RS-232 communications.
Communications signals TXD and RXD also connect to general purpose Port S signals.
Table 4: COM Connections
MCU Port COM Signal I/O PORT
CONNECTOR
PS1/TXD TXD OUT J1-5
PS0/RXD RXD IN J1-7

DEMO9S12XDT512 JULY 18, 2008
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COM Connector
A standard 9-pin Dsub connector provides external connections for the SCI0 port. The Dsub
shell is connected to board ground through a ferrite bead. The ferrite bead provides noise
isolation on the RS-232 connection. The figure below details the DB9 connector.
Figure 6: COM Connector
16
TXD 27RTS
RXD 38CTS
49NC
GND 5
Female DB9 connector that interfaces to the MCU internal SCI0 serial
port via the RS232 transceiver. It provides simple 2 wire asynchronous
serial communications without flow control. Flow control is provided at
test points on the board.
Pins 1, 4, and 6 are connected together.
LIN Communications
The DEMO9S12XDT512 applies the MC33661D Local Interconnect Interface (LIN) physical
layer (PHY) for use in developing automotive control applications. The MC33661D physical
layer interface (PHY) supports LIN bus functionality for input voltages between +6V and +18V.
Only power applied to the PWR connector will enable the LIN bus. Two, 4-pin, Molex con-
nectors provide off-board connectivity. The figure below shows the pin-out of the LIN connec-
tor looking into the connector.
Figure 7: LIN Connector
LIN I/O 4 3 VSUP
GND 2 1 GND REF: Mating Connector, Molex P/N,
39-01-2040, Housing
39-00-0039, Socket
NOTE: Board must be powered from the PWR connector with VIN between +6V and +18V.
LIN_EN
The LIN_EN option header enables or disables the LIN driver on SCI1.
Figure 8. LIN_EN Option Header
LIN_EN
4 3 TX Enable LIN TX
2 1 RX Enable LIN RX
NOTE: Board must be powered from the PWR connector with VIN between +6V and 18V.

DEMO9S12XDT512 JULY 18, 2008
14
CAN Communications
The DEMO9S12XDT512 provides a PCA82C250 high-speed CAN physical layer interface
(PHY). A 3-pin connector provides connectivity to the off-board CAN bus. The CAN PHY
connects to the CAN0 channel on the MCU. The PHY supports data rates up to 1 MBps with
edge-rate control to reduce EMI/RFI. The figure below shows the pin-out of the CAN_PORT
connector.
Figure 9. CAN_PORT Connector
1CAN_H
2GND
3CAN_L
The CAN PHY connects to the CAN0
channel in the MCU
MODE
The MODE option header allows the MCU to be configured between the various modes of op-
eration. Refer to the MC9S12XDP512 Device User Guide for further details on operational
modes. Although no external memory is available on the DEMO9S12XDT512 board, external
bus signals are available at expansion headers J1 and J2. The figure below shows the set-
tings for the MODE option header. MODE selection status is latched at the rising edge of RE-
SET. An internal pull-down biases the MODA and MODB signals during boot. After RESET,
the MODA and MODB signals revert to general-purpose I/O functionality.
The MODE option header is not installed in default configuration. Internal bias configures the
MCU for single-chip operation out of reset. To configure the MCU for expanded mode opera-
tion, install a 2x2 pin header and install shunts as noted below.
Figure 10. MODE Option Header
Installed Removed
4 3 MODB MODB = 1 MODB = 0
2 1 MODA MODA = 1 MODA = 0
MODE
NOTE: MODE selection pin status is latched on the rising edge of RESET
NOTE: This header is not installed in default configuration
VRH/VRL
MCU inputs VRH and VRL provide the upper and lower voltage reference for the analog to
digital (ATD) converter. By default, VRH is tied to VDD and VRL is tied to ground. Adequate
filtering has been added to provide a voltage reference with minimal ripple. Either, or both,
references may be isolated to provide alternate ATD input references. A test point via on each
signal, labeled VRH, or VRL, provides a convenient attach point.

DEMO9S12XDT512 JULY 18, 2008
15
A 0-ohm configuration resistor allows isolation of each reference voltage. Removing R10 iso-
lates VRH while removing R12 isolates VRL. Install 0805 sized 0-ohm resistors in these loca-
tions to restore the board to default configuration.
Care must be exercised when using alternate input references. The associated isolation re-
sistor must be removed before applying an alternate voltage reference or the board may be
damaged. The table below summarizes the changes necessary to use alternate VRH and/or
VRL.
Table 5: ATD Reference Voltage
Installed (Default) Removed
R10 VRH = VDD VRH provided by user
R12 VRL = GND VRL provided by user
NOTE: Damage to the board may result if an alternate reference voltage is attached without
first removing the associated configuration resistor.
USER I/O
User I/O includes 2 push button switches, one 4-position DIP switch, 4 green LEDs, a potenti-
ometer, and a Light Sensor. The sections below provide details on each User I/O. The User
option header block enables or disables each User I/O individually.
SWITCHES
The DEMO9S12XDT512 target board provides 2 push button switches and one 4-position DIP
switch for user input. Each push button switch is an active low input with a pull-up resistor bias
to prevent indeterminate input conditions. Pressing a push-button switch causes a low logic
input on the associated input.
Each DIP switch position is an active low input. Use of the DIP switches requires enabling the
associated PORTB pull-ups internal to the MCU prevent indeterminate input conditions. Mov-
ing a DIP switch position to ON causes a low logic level on the associated input. The figure
below shows the USER enable position and associated signal for each user switch.
LED’s
The DEMO9S12XDT512 target board provides 4 green LEDs for output indication. Each LED
is an active low output. A series, current-limit resistor prevents excessive diode current. Writ-
ing a low logic level to an LED output causes the associated LED to turn on. The figure below
shows the USER enable position and associated signal for each user LED.

DEMO9S12XDT512 JULY 18, 2008
16
POT
A single-turn, 3/8 inch, 5K ohm trimmer potentiometer (POT) has been provided as user, ana-
log input. The part is decoupled to minimize noise during adjustment. The POT connects to
analog input PAD05/AN05 on the MCU. The figure below shows the USER enable position
and associated signal for the potentiometer.
LIGHT SENSOR
A 4mm photocell light sensor exhibiting 23K – 33K ohms of output resistance has been pro-
vided. Output resistance is inversely related to incident light intensity. A gain stage (U5) am-
plifies the sensor output before connecting to the MCU. The SENSOR connects to analog in-
put PAD04/AN04 on the MCU. The figure below shows the USER enable position and associ-
ated signal for the Light Sensor
User Signals
The following table shows the connections for each user I/O device.
Table 6: User I/O
USER Ref Des Signal Device
1SW1 PP0/KWP0/PWM0/MISO1 Push Button Switch
2SW2 PP1/KWP1/PWM1/MOSI1 Push Button Switch
3SW3-1 PB0 4-pos DIP Switch
4SW3-2 PB1 4-pos DIP Switch
5SW3-3 PB2 4-pos DIP Switch
6SW3-4 PB3 4-pos DIP Switch
7LED1 PB4 Green LED
8LED2 PB5 Green LED
9LED3 PB6 Green LED
10 LED4 PB7 Green LED
11 RV1 PAD05/AN05 Potentiometer
12 RZ1 PAD04/AN04 Light Sensor
USER ENABLE
The User option header block enables or disables each User I/O device individually. User I/O
includes 4 green LEDs, 2 push button switches, one 4-position DIP switch, a Light Sensor, and
a potentiometer. Installing a shunt enables the associated option. Removing a shunt disables
the associated option. The table below shows the configuration option for each USER I/O.

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Table 7: USER Option Header
Shunt
USER Installed Removed Description
SW1 1 2 Enable Disable Push Button Switch 1
SW2 3 4 Enable Disable Push Button Switch 2
SW3-1 5 6 Enable Disable DIP Switch Position 1
SW3-2 7 8 Enable Disable DIP Switch Position 2
SW3-3 910 Enable Disable DIP Switch Position 3
SW3-4 11 12 Enable Disable DIP Switch Position 4
LED1 13 14 Enable Disable LED 1
LED2 15 16 Enable Disable LED 2
LED3 17 18 Enable Disable LED 3
LED4 19 20 Enable Disable LED 4
RV1 21 22 Enable Disable Potentiometer
RZ1 23 24 Enable Disable Light Sensor
MCU I/O PORT
The MCU I/O PORT connectors (J1 and J2) provide access to the MC9S12XDT512 I/O sig-
nals. The figures below show the pin-out for each MCU I/O connector.
Figure 11: MCU I/O PORT – J1
J1
VDD 1 2 IRQ/PE1
VSS 3 4 RESET*
PS1/TXD0 5 6 MODC/BKGD
PS0/RXD0 7 8 PP7/KWP7/PWM7/SCK2
PP0/KWP0/PWM0/MISO1 910 PAD07/AN07
PP1/KWP1/PWM1/MOSI1 11 12 PAD06/AN06
PT0/I0C0 13 14 PAD05/AN05
PT1/IOC1 15 16 PAD04/AN04
PM4/RXCAN2/RXCAN0/RXCAN4/MOSI0 17 18 PAD03/AN03
PM2/RXCAN1/RXCAN0/MISO0 19 20 PAD02/AN02
PM5/TXCAN2/TXCAN0/TXCAN4/SCK0 21 22 PAD01/AN01
PM3/TXCAN1/TXCAN0/SS0 23 24 PAD00/AN00
PA7 25 26 PJ6/KWJ6/RXCAN4/SDA0
PA6 27 28 PJ7/KWJ7/TXCAN4/SCL0
PA5 29 30 PP2/KWP2/PWM2/SCK1
PA4 31 32 PP3/KWP3/PWM3/SS1
PA3 33 34 PP4/KWP4/PWM4/MISO2
PA2 35 36 PP5/KWP5/PWM5/MOSI2
PA1 37 38 PS2/RXD1
PA0 39 40 PS3/TXD1

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Figure 12. MCU I/O PORT – J2
J2
PB0 41 42 PM0/RXCAN0/RXB
PB1 43 44 PM1/TXCAN0/TXB
PB2 45 46 IOC2/PT2
PB3 47 48 IOC3/PT3
PB4 49 50
PB5 51 52
PB6 53 54
PB7 55 56
IOC4/PT4 57 58
IOC5/PT5 59 60
IOC6/PT6 61 62
IOC7/PT7 63 64
PE7/XCLKS 65 66
PE6/MODB 67 68
PE5/MODA 69 70
PE4/ECLK 71 72
PE3 73 74
PE2 75 76
77 78
PE0/XIRQ* 79 80

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APPENDIX A
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