Software Design

5.5.3 I/O Usage

Table 5-2summarizes the use of the I/O pins.

 

 

 

 

 

 

Table 5-2. I/O Usage

 

 

 

 

 

 

I/O pin

Direction

 

 

 

Purpose

 

 

 

 

 

 

PTC0/OSC1

INPUT

 

 

 

OSC1(EXTERNAL OSCILLATOR IN MONITOR MODE)

 

 

 

 

 

 

PTC1/OSC2

-

 

 

 

UNUSED

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(MAINS ZERO CROSSING DETECTION/

 

IN MONITOR

 

 

 

 

 

 

 

 

IRQ

IRQ

PTC2/SHTDWN/IRQ

INPUT

 

 

 

 

 

MODE)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PTB0/TOP

OUTPUT

 

 

 

TOP (HRP OUTPUT)

 

 

 

 

 

 

PTB1/BOT

OUTPUT

 

 

 

BOT (HRP OUTPUT)

 

 

 

 

 

 

PTB2/FAULT

-

 

 

 

UNUSED

 

 

 

 

 

 

PTB3/PWM0

OUTPUT

 

 

 

PWM0 (REFERENCE SINUS WAVE GENERATING)

 

 

 

 

 

PTB4/PWM1

OUTPUT

 

 

SWITCHING PFC TRANSISTOR ONLY IN DCM HW VARIATION

 

 

 

 

 

 

PTB5/V+

INPUT

 

 

 

V+ (COMPARATOR INPUT)

 

 

 

 

 

 

PTB6/V-

INPUT

 

 

 

V- (COMPARATOR INPUT)

 

 

 

 

 

 

 

 

 

PTB7/VOUT/ADC6/FAULT

OUTPUT

 

 

VOUT (COMPARATOR OUTPUT) AND MOREOVER AS PWM

 

 

 

FAULT PIN IN DCM HW VARIATION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PTA0/ADC0/KBI0

INPUT/OUTPUT

 

PTA0 (COMMUNICATION PIN IN MONITOR MODE AND FOR

 

 

SERIAL BOOTLOADER PROGRAMMING)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PTA1/ADC1/KBI1

INPUT

 

 

ADC1 (LUMINANCE LEVEL /PTA1 IN MONITOR MODE)

 

 

 

 

 

 

PTA2/ADC2/KBI2

INPUT

 

 

 

ADC2 (DC-BUS VOLTAGE)

 

 

 

 

 

 

PTA3/ADC3/KBI3

INPUT

 

 

 

ADC3 (TUBE CURRENT 1)

 

 

 

 

 

 

PTA4/ADC4/KBI4

INPUT

 

 

 

ADC4 (TUBE CURRENT 1

 

 

 

 

 

 

 

 

 

 

 

OUTPUT

 

 

 

PTA5 (USER LED)

PTA5/RST/KBI5

 

 

 

 

 

 

 

 

 

PTA6/ADC5/TCH0/KBI6

INPUT

 

 

 

ADC5 (TUBE VOLTAGE DIFFERENCE

 

 

 

 

 

 

 

 

 

 

 

 

The installation CodeWarrior Version 3 Service Pack for LB8 is part of the Emulation Board software. This includes examples of how to tune and work with the HRP.

5.6 Definitions of Constants and Variables

This section provides definitions of the constants and variables used in the program. The definitions can be divided into two parts:

System setup definitions

System constants and variables

Dimmable Light Ballast with Power Factor Correction, Rev. 1

52

Freescale Semiconductor

Page 52
Image 52
Freescale Semiconductor M68HC08 manual Definitions of Constants and Variables, 3 I/O Usage

M68HC08 specifications

Freescale Semiconductor, known for its innovative solutions in the field of embedded systems, developed the M68HC08 microcontroller family, which includes the MC68HC908QT2. This 8-bit microcontroller is engineered to meet the demands of diverse applications, including automotive, industrial, and consumer electronics.

The MC68HC908QT2 is designed around Freescale’s M68HC08 core, which is renowned for its efficient and reliable performance. This microcontroller integrates a powerful instruction set, enabling developers to create high-performance applications with relatively low power consumption. The device operates at a clock frequency of up to 3 MHz, which is adequate for various control tasks.

One of the key features of the MC68HC908QT2 is its memory architecture. It includes a 2 KB Flash memory for program storage, representing a significant advantage for developers requiring non-volatile memory. Additionally, it encompasses 128 bytes of EEPROM memory, allowing for data retention even after power loss. The microcontroller also has 256 bytes of RAM for efficient data manipulation during operation.

In terms of input/output capabilities, the MC68HC908QT2 supports a variety of interfacing options. The microcontroller features up to 20 general-purpose I/O pins for flexibility in connecting with peripheral devices. Additionally, it provides multiple analog-to-digital converters (ADC) and timers that facilitate efficient analog signal processing and precise control through timing functions.

The architecture of the MC68HC908QT2 also incorporates sophisticated on-chip peripherals, enhancing its functionality. These peripherals include PWM (Pulse Width Modulation) outputs, which are essential for applications requiring motor control and other precise duty cycle processes. The integrated watchdog timer ensures reliable operation by resetting the system in the event of an application failure.

Moreover, the MC68HC908QT2 is equipped with an efficient power management system, enabling operation in a low-power mode, ideal for battery-powered applications. This microcontroller is packaged in a compact 28-pin dual in-line package (DIP), making it suitable for space-constrained designs.

In summary, the Freescale Semiconductor MC68HC908QT2 microcontroller is distinguished by its robust performance, extensive memory options, and versatile I/O capabilities. Its advanced features, including built-in timers, ADC, and a power management system, make it an exceptional choice for developers seeking to implement reliable and efficient embedded solutions. With its comprehensive architecture, the MC68HC908QT2 remains a popular choice in the landscape of 8-bit microcontrollers.