General Description

Technical Data MC68HC908AZ60A — Rev 2.0

40 General Description MOTOROLA

NOTE: The following pin descriptions are just a quick reference. For a more

detailed representation, see Input/Output Ports on page 353.

1.5.1 Power Supply Pins (V

and V

)

and V

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

1-6. Place the C1 bypass capacitor as close to the MCU as possible. Use

a high-frequency response ceramic capacitor for C1. C2 is an optional

bulk current bypass capacitor for use in applications that require the port

pins to source high current levels.

is also the ground for the port output buffers and the ground return

for the serial clock in the Serial Peripheral Interface module (SPI). See

Serial Peripheral Interface (SPI) on page 285.

NOTE: V

must be grounded for proper MCU operation.

Figure 1-6. Power supply bypassing

MCU

0.1

µF

NOTE: Component values shown represent typical applications.

General Description

Pin Assignments

MC68HC908AZ60A — Rev 2.0 Technical Data

MOTOROLA General Description 41

1.5.2 Oscillator Pins (OSC1 and OSC2)

The OSC1 and OSC2 pins are the connections for the on-chip oscillator

circuit. See Clock Generator Module (CGM) on page 169.

1.5.3 External Reset Pin (RST

)

A logic 0 on the RST

pin forces the MCU to a known startup state. RST

is bidirectional, allowing a reset of the entire system. It is driven low when

any internal reset source is asserted. See System Integration Module

(SIM) on page 147 for more information.

1.5.4 External Interrupt Pin (IRQ)

IRQ is an asynchronous external interrupt pin. See External Interrupt

Module (IRQ) on page 235.

1.5.5 Analog Power Supply Pin (V

DDA

)

DDA

is the power supply pin for the analog portion of the Clock

Generator Module (CGM). See Clock Generator Module (CGM) on

page 169.

1.5.6 Analog Ground Pin (V

SSA

)

SSA

is the ground connection for the analog portion of the Clock

Generator Module (CGM). See Clock Generator Module (CGM) on

page 169.

1.5.7 External Filter Capacitor Pin (CGMXFC)

CGMXFC is an external filter capacitor connection for the Clock

Generator Module (CGM). See Clock Generator Module (CGM) on

page 169.

General Description

Technical Data MC68HC908AZ60A — Rev 2.0

42 General Description MOTOROLA

1.5.8 ADC Analog Power Supply Pin (V

DDAREF

)

DDAREF

is the power supply pin for the analog portion of the Analog-to-

Digital Converter (ADC). See Analog-to-Digital Converter (ADC) on

page 471.

1.5.9 ADC Analog Ground Pin (AV

REFL

)

The AV

REFL

pin provides both the analog ground connection and

the reference low voltage for the Analog-to-Digital Converter (ADC). See

Analog-to-Digital Converter (ADC) on page 471.

1.5.10 ADC Reference High Voltage Pin (V

REFH

)

REFH

provides the reference high voltage for the Analog-to-Digital

Converter (ADC). See Analog-to-Digital Converter (ADC) on page

471.

1.5.11 Port A Input/Output (I/O) Pins (PTA7–PTA0)

PTA7–PTA0 are general-purpose bidirectional I/O port pins. See

Input/Output Ports on page 353.

1.5.12 Port B I/O Pins (PTB7/ATD7–PTB0/ATD0)

Port B is an 8-bit special function port that shares all eight pins with the

Analog-to-Digital Converter (ADC). See Analog-to-Digital Converter

(ADC) on page 471 and Input/Output Ports on page 353.

1.5.13 Port C I/O Pins (PTC5–PTC0)

PTC5–PTC3 and PTC1–PTC0 are general-purpose bidirectional I/O

port pins. PTC2/MCLK is a special function port that shares its pin with

the system clock which has a frequency equivalent to the system clock.

See Input/Output Ports on page 353.

Part #	8A/S6
Description	Incandescent S Light Lamp
Category	LAMP
Availability	In Stock
Qty	2

8A/S6

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