mc68hc908kx8 Freescale Semiconductor, Inc, mc68hc908kx8 Datasheet - Page 20

• Manufacturer Part Number: mc68hc908kx8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

General Description
1.4 Pin Assignments
Figure 1-2
1.4.1 Supply Pins (V
V
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
response ceramic capacitors for C
applications that require the port pins to source high-current levels.
20
DD
and V
1-3. Place the bypass capacitors as close to the MCU power pins as possible. Use high-frequency
SS
shows the pin assignments for MC68HC908KX8.
are the power supply and ground pins. The MCU operates from a single power supply.
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
DD
and V
Figure 1-2. PDIP and SOIC Pin Assignments
Note: Component values shown represent typical applications.
Figure 1-3. Power Supply Bypassing
Bypass
SS
PTA1/KBD1
PTA0/KBD0
PTB0/AD0
PTB1/AD1
PTB2/AD2
PTB3/AD3
)
V
DD
IRQ1
V
V
DD
. C
SS
Bulk
1
2
3
4
5
6
7
8
are optional bulk current bypass capacitors for use in
C
0.1 µF
+
C
Bypass
MCU
Bulk
16
15
14
13
12
11
10
9
V
PTA4/KBD4
PTA3/KBD3/TCH1
PTA2/KBD2/TCH0
PTB4/RxD
PTB5/TxD
PTB6/(OSC1)
PTB7/(OSC2)/RST
DD
V
SS
Freescale Semiconductor