AN2600 Freescale Semiconductor / Motorola, AN2600 Datasheet - Page 4

• Manufacturer Part Number: AN2600
• Description: A Simple Keypad Using LIN with the MC68HC908QT/QY MCU
• Manufacturer: Freescale Semiconductor / Motorola

AN2600/D
4
Vbat
GND
LIN
DIODE
10k
6
3
LIN
Wake
MC33399
A Simple Keypad Using LIN with the MC68HC908QT/QY MCU
The LIN driver uses the pin PTA1 for LIN Rx channel. This is a fixed
configuration because PTA1 is the timer channel 1 (TCH1) pin. Any GPIO port
can be used for the LIN Tx channel. In this application, it is the PTB2 pin. The
switches are connected to port B with pull-up resistors activated. The signalling
LED is linked to pin PTA3.
1k
Freescale Semiconductor, Inc.
Figure 1. Keypad Module Circuit Diagram
For More Information On This Product,
EN
RX
TX
8
5
27k
LED
IN
SHDN
2
1
4
LT1121
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OUT
47k
1
12
11
13
2
4
5
8
100n
PTB7
PTA1/AD1/TCH1
PTB2
PTA0/AD0/TCH0
PTA5/OSC1
PTA4/OSC2
PTA3/RST
MC68HC908QY
PTA2/IRQ
PTB0
PTB1
PTB3
PTB4
PTB5
PTB6
15
14
10
7
6
3
9
KEY A
KEY B
KEY C
KEY D
KEY E
KEY F
KEYPAD
MOTOROLA