MC68HC05P18 Datasheet, PDF (21/144 Pages) Freescale Semiconductor, Inc – Advance Information

Freescale Semiconductor, Inc.
General Description
Functional Pin Description
RESET
1
IRQ
2
PA7
3
PA6
4
PA5
5
PA4
6
PA3
7
PA2
8
PA1
9
PA0
10
SDO/PB5
11
SDI/PB6
12
SCK/PB7
13
V_SS
14
28
V_DD
27
OSC1
26
OSC2
25
PD7/TCAP
24
TCMP
23
PD5/CKOUT
22
PC0
21
PC1
20
PC2
19
PC3/AD3
18
PC4/AD2
17
PC5/AD1
16
PC6/AD0
15
PC7/V_REFH
Figure 1-2. User Mode Pinout
1.5.1 V_DD and V_SS
Power is supplied to the MCU through V_DD and V_SS. V_DD is connected
to a regulated positive supply and V_SS is connected to ground.
Very fast signal transitions occur on the MCU pins. The short rise and
fall times place very high short-duration current demands on the power
supply. To prevent noise problems, take special care to provide good
power supply bypassing at the MCU. Use bypass capacitors with good
high-frequency characteristics and position them as close to the MCU as
possible. Bypassing requirements vary, depending on how heavily the
MCU pins are loaded.
1.5.2 OSC1 and OSC2
The OSC1 and OSC2 pins are the control connections for the on-chip
oscillator. The OSC1 and OSC2 pins can accept:
• A crystal as shown in Figure 1-3(a)
• A ceramic resonator as shown in Figure 1-3(a)
• An external clock signal as shown in Figure 1-3(b)
MC68HC(8)05P18 — Rev. 2.0
MOTOROLA
General Description
For More Information On This Product,
Go to: www.freescale.com
Advance Information
21