Demonstration Board User's Guide

DEMO9S08AC60E User’s Guide, Rev. 0.1
Freescale Semiconductor 19
1.13.3 Rocker Switches
Eight rocker switches (SW5) are provided for user application development.
These switches are active low and input a logic low when set to the closed
position. There are no external pullups on these switches so the internal pullups
should be enabled on the MCU port pins to ensure proper operation. Port A pins
can be disconnected from the rocker switches by removing the appropriate
jumper. The rocker switches are connected as described below
Table 1-10 Rocker Switch (SW5) Connections
Switch MCU Port Jumper
1 PTA0 J24
2 PTA1 J25
3 PTA2 J26
4 PTA3 J27
5 PTA4 J28
6 PTA5 J29
7 PTA6 J30
8 PTA7 J31
1.13.4 Accelerometer
A Freescale MMA6270QT accelerometer (U5) is provided to assist users in
developing accelerometer based application code. The MMA6270QT provides
output data in the X and Y direction and has a sleep mode. The MMA6270QT
is a 3.3V part and is connected to the MC9S08AC60 through the use of a level
translator. The X and Y outputs are connected back to the MCU both directly
from the accelerometer (3.3V signals) and amplified to 5V through the use of
op-amps. The sleep mode is an active low input to the accelerometer. When a
logic low is applied to the sleepmode pin the device outputs are turned off,
providing significant reduction of operating current (low to 3 uA typically). The
MCU port pins can be disconnected from the accelerometer by removing the
appropriate jumper. The accelerometer is connected as described below