MC68HC908KX8 Datasheet, PDF (33/310 Pages) Motorola, Inc – Microcontrollers

General Description
Pin Assignments
1.5 Pin Assignments
Figure 1-2 shows the pin assignments for MC68HC908KX8.
V_SS 1
PTA1/KBD1 2
PTA0/KBD0 3
IRQ1 4
PTB0/AD0 5
PTB1/AD1 6
PTB2/AD2 7
PTB3/AD3 8
16 V_DD
15 PTA4/KBD4
14 PTA3/KBD3/TCH1
13 PTA2/KBD2/TCH0
12 PTB4/RxD
11 PTB5/TxD
10 PTB6/(OSC1)
9 PTB7/(OSC2)/RST
Figure 1-2. PDIP and SOIC Pin Assignments
1.5.1 Supply Pins (V_DD and V_SS)
V_DD and V_SS are the power supply and ground pins. The MCU operates
from a single power supply.
Fast signal transitions on MCU pins place high, short-duration current
demands on the power supply. To prevent noise problems, take special
care to provide power supply bypassing at the MCU as shown in
Figure 1-3. Place the bypass capacitors as close to the MCU power pins
as possible. Use high-frequency response ceramic capacitors for
C_Bypass. C_Bulk are optional bulk current bypass capacitors for use in
applications that require the port pins to source high-current levels.
1.5.2 Oscillator Pins (OSC1 and OSC2)
The OSC1 and OSC2 pins are available through programming options
in the configuration register. These pins then become the connections to
an external clock source or crystal/ceramic resonator. PTB7 and PTB6
are not available for the crystal/ceramic resonator option and PTB6 is
unavailable for the external clock source option.
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 — Rev. 1.0
MOTOROLA
General Description
Technical Data
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