DEMO908QB8 Freescale Semiconductor, DEMO908QB8 Datasheet - Page 16

• Manufacturer Part Number: DEMO908QB8
• Description: BOARD DEMO FOR MC68HC908QB8
• Manufacturer: Freescale Semiconductor
• Type: MCUr

Specifications of DEMO908QB8

• Contents: *
• Processor To Be Evaluated: MC908QB8
• Data Bus Width: 8 bit
• Interface Type: RS-232, USB
• Silicon Manufacturer: Freescale
• Core Architecture: HC08
• Core Sub-architecture: HC08
• Silicon Core Number: MC68HC908
• Silicon Family Name: HC08Q
• Kit Contents: MC68HC908QB8, Cables, Guides
• Rohs Compliant: No
• For Use With/related Products: MC68HC908QB8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

D E M O 9 0 8 Q B 8
LED Indicators
Indicators LED1 and LED2 are enabled from HC08 I/O ports by the USER option bank. Each
LED is active low and illuminating when a logic low signal is driven from the respective MCU
I/O port. MCU ports PTB6 and PTB7 drive LED1 and LED2 respectively. The table below
details the user jumper settings.
Potentiometer
A 5k Ω, thumb-wheel type, potentiometer at RV1 provides variable resistance input for user
applications. The output is the result of a voltage divider that changes as the thumb-wheel is
turned. This device is connected to the MCU on signal PTA0. The table below details the user
jumper settings.
The potentiometer is not available while in monitor mode. Using the potentiometer requires
disabling the MON08 COM signal. This requires removing USB-MON08 Enable jumper ‘D’.
Otherwise results may be unpredictable.
Photocell
A photoconductive photocell provides light sensitive, variable resistance input for user applica-
tions. Device resistance is inversely proportional to light intensity incident on the surface of the
device. A rail-to-rail OP amp at U2 boosts the photocell output to useable levels. This signal
is available to the MCU on signal PTA1. The table below details the user jumper settings.
Table 5: User Option Jumper Settings
NOTE: User-5 option jumper must be removed to enter monitor mode.
NOTE: USB-MON08 ENABLE-D jumper must be removed to use this function.
NOTE: User-6 option jumper must be removed to enter monitor mode. The jumper may be
NOTE: USER-5 and USER-6 must be disabled to enter Monitor mode
Jumper
User-1
User-2
User-3
User-4
User-5
User-6
reinstalled after RESET.
On
Enable SW1
Enable SW2
Enable LED1
Enable LED2
Enable RV1
Enable RZ1
16
Off
Disable SW1
Disable SW2
Disable LED1
Disable LED2
Disable RV1
Disable RZ1
MCU PORT
PTA5 (U1-4)
PTA4 (U1-5)
PTB6 (U1-3)
PTB7 (U1-2)
PTA0 (U1-13)
PTA1 (U1-12)
M A R C H
1 8 ,
2 0 0 5