Freescale Semiconductor Demonstration Board DEMO9S08AC60E Manual Do Utilizador

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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