MC68HC05P4A Datasheet, PDF (14/72 Pages) Advanced Analogic Technologies – Microcontrollers

General Description
1.5 Pin Assignments
The MC68HC05P4A pin assignments are shown in Figure 1-2.
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
TCAP/PD7
24
TCMP
23
PD5
22
PC0
21
PC1
20
PC2
19
PC3
18
PC4
17
PC5
16
PC6
15
PC7
Figure 1-2. Pin Assignments
1.6 Signal Description
The following paragraphs provide a description of the signals.
1.6.1 V_DD and V_SS
Power is supplied to the microcontroller through V_DD and V_SS. V_DD is the power supply and V_SS is ground.
1.6.2 IRQ
This pin has a mask option that provides two different choices of interrupt triggering sensitivity. The IRQ
pin contains an internal Schmitt trigger as part of its input to improve noise immunity. Refer to Chapter 3
Central Processor Unit (CPU) for more detail.
1.6.3 OSC1 and OSC2
These pins provide control input for an on-chip clock oscillator circuit. A crystal, a ceramic resonator, a
resistor/capacitor combination, or an external signal connects to these pins and provides a system clock.
A mask option selects either a crystal/ceramic resonator or a resistor/capacitor as the frequency
determining element. The oscillator frequency is two times the internal bus rate.
MC68HC05P4A Data Sheet, Rev. 7.1
14
Freescale Semiconductor