Software Design

 

 

for timing 1 ms intervals.

8.

extern tU08

curr_T1;

 

This variable represents the current in tube 1.

9.

extern tU08

curr_T2;

 

This variable represents the current in tube 2.

10.extern tU08 avg_CurrentT1T2;

This variable represents the average value of the tube currents.

11.

extern tU16

mscounter;

 

This variable counts 1 ms intervals. It is incremented every 1 ms. It is used for application timing.

12.

extern tU08

sineGain;

 

This variable represents the gain of the reference sine waveform.

13.

extern tU16

timCntVal;

 

This variable represents an auxiliary variable used to get the timer value required to trim the

 

internal oscillator to the reference frequency (frequecy of mains * 2)

14.

extern tU08

aux;

 

This variable represents an auxiliary variable.

15.

extern tU16

ramp;

 

This variable represents an auxiliary variable (HRP frequency) for dimming by ramping.

16.

extern tU08

currFltCNT;

 

This variable represents the number of fault states occurring during run mode.

17.

extern tU08

currFltMS;

 

This variable counts the zero current checking interval. It is incremented every 1 ms.

18.

extern tU08

ignitFltCNT;

 

This variable represents the number of fault states occurring during tube ignition.

19.extern tU16 integralPortionK_1;

This variable represents integral n-1 value of the PI PFC stage regulator.

20.extern tU08 proportionalGain;

This variable represents proportional gain of the PI PFC stage regulator.

21.

extern

tU08

integralGain;

 

This variable represents integral gain of the PI PFC stage regulator.

22.

extern

tU08

uCreq;

 

This variable represents the required value of the DC-bus voltage.

23.extern tU16 integralPortionK_1I;

This variable represents integral n-1 value of the PI ballast stage regulator.

24.extern tU08 proportionalGainI;

This variable represents proportional gain of the PI ballast stage regulator.

25.

extern tU08

integralGainI;

 

This variable represents integral gain of the PI ballast stage regulator.

26.

extern

tU08

req_Cur;

 

This variable represents the actual value of the required dimming value.

27.

extern

tU08

time500us;

This variable counts PWM interrupts. The variable is incremented at every PWM interrupt. It is used for timing 500 us intervals.

Dimmable Light Ballast with Power Factor Correction, Rev. 1

56

Freescale Semiconductor

Page 56
Image 56
Freescale Semiconductor M68HC08 manual Extern tU08 CurrT1

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.