CMD-12DP512 AXIOM, CMD-12DP512 Datasheet - Page 13

• Manufacturer Part Number: CMD-12DP512
• Description: Single Board Computer
• Manufacturer: AXIOM

Specifications of CMD-12DP512

• Silicon Manufacturer: Freescale
• Core Architecture: HCS12
• Core Sub-architecture: S12D
• Features: Onboard Back Ground Debug, Breadboard And Prototype Area
• Kit Contents: Board
• Silicon Family Name: S12D
• Silicon Core Number: MC9S12DP512

C M D - 1 2 D P 5 1 2
CAN Port
CAN_EN Option
CAN_EN installed provides the CAN RX signal to the HCS12 CAN-0 RX input pin (port PM0).
Open the enable option to apply the HCS12 Port PM0 pin for other applications.
Cut-Away #6, CAN BUS TRANSMIT ENABLE
The CAN port transceiver transmit driver is enabled by default for maximum drive and
minimum slew rate by default. The drive and slew rate may be adjusted by cutting CUT-AWAY
#6 and adding an 0805 size surface mount resistor, see the PCA82C250 data sheet for more
information.
CAN Bus transceiver transmit enable control can be applied to the port by the RS tie pad.
The user should select an available HCS12 I/O port to perform the transmit enable function
and connect it from the MCU_PORT pin to RS pad as required. The CUT_AWAY #6 must be
open to apply transmit enable control. The transmit enable signal to the CAN transceivers is
active logic low.
CUT-AWAY options allow the user to disconnect dedicated HCS12 I/O port resources from
development board peripherals.
connection again by installing surface mount 0805 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.
The CAN port provides RC1 as 120 Ohms to terminate the CAN bus. User may change this
0805 size SMT resistor if required for application.
JP2 Option
JP2 is provided for possible future USB BDM firmware updates. JP2 should remain open for
normal operation of the USB port.
USER Accessory Ports
The LCD Port, Keypad Port, and USER I/O connector provide access to the user application
accessory ports or on-board user indicators and switches.
1 = Ground
2 = CAN-HI
3 = CAN-LO
R E V
Board Top Edge side of connector
B .
The CUT-AWAY options also allow for establishing the
CAN BUS TERMINATION
13
0 8 / 2 3 / 0 7