User guide

CML12SDP256 10/10/02

CUT-AWAY OPTIONS 1 - 6

CUT-AWAY options allow the user to disconnect dedicated HCS12 I/O port resources from

development board peripherals. The CUT-AWAY options also allow for establishing the

connection again by installing surface mount 1206 size 0 ohm resistors or mod wire with the

use of a soldering iron. Normal operation of the development board generally does not require

any manipulation of the CUT_AWAY options.

#1 Cut-Away: HCS12 Port S5/MOSI signal to the LCD_PORT shift register.

#2 Cut-Away: HCS12 Port S7/SS0 signal to the LCD_PORT shift register.

#3 Cut-Away: HCS12 Port S6/SCK signal to the LCD_PORT shift register.

#4 Cut-Away: HCS12 Oscillator Crystal ground, if another crystal is applied by the user this

connection may require a capacitor to be installed. Refer to the HCS12 CGM module

information.

#5 Cut-Away: HCS12 Port M0/CAN_RXD0 signal to the CAN port transceiver.

#6 Cut-Away: CAN Port Transceiver enable connection to ground. This connection enables

the CAN Port transceiver output to the CAN bus at all times. If the user wants to apply output

enable or slew rate control to the transceiver, this option should be cut and 1206 size resistor

applied for slew rate or a HCS12 I/O port applied for output enable control. See the

PCA82C250 data sheet for application information.

PORTS AND CONNECTORS

TB1 and J1 Power

The TB1 and J1 connectors provide power input to the board or if J1 is used for input, TB1

maybe used to source additional circuitry. The J1 power jack accepts a standard 2.0 ~ 2.1mm

center barrel plug connector (positive voltage center) to provide the +VIN supply of +7 to +20

VDC @ 80ma minimum (+9VDC nominal). TB1 provides access to the +VIN, GND (power

ground), HCS12 core VDD, and +5V power supplies. The CML12Sxxx power supply will

provide 50ma of +5V for user application. +VIN input power should only be applied by J1 or

TB1, not both or a supply conflict may occur and the CML12Sxxx board could be damaged.

The VDD supply is for reference or external 2.5V input only and should not be loaded by

external circuitry or damage to the HCS12 device may occur.