CHAPTER 7 8-BIT PWM TIMER

7.10Program Example for PWM Timer

This section describes program examples of an 8-bit PWM timer.

■Program Example of Interval Timer Functions

●Processing specifications

•5 ms interval timer interrupts occur repeatedly.

•The square waveform that inverts at an interval is output to the P50/PWM pin.

•The following expression yields the COMR register value for which the interval is about 5 ms when the top speed of the gear (one instruction cycle = 4/FCH) is obtained at an oscillation frequency of 12.5 MHz. The count clock is 64 tINST of the internal count clock.

COMR register value = 5 ms/(64 ⋅ 4/12.5 MHz) - 1 = 244.1 (0F4H)

●Coding example

CNTR

EQU

0022H

;

Address of the PWM control register

COMR

EQU

0023H

;

Address of the PWM compare register

TPE

EQU

CNTR:3

;

Defining the bit to enable the counter operation

TIR

EQU

CNTR:2

;

Defining the interrupt request flag bit

ILR3

EQU

007D

;

Address of the register to set the interrupt level

INT_V

DSEG

ABS

;

[DATA SEGMENT]

 

ORG

0FFF8H

 

 

IRQ9

DW

WARI1

;

Setting the interrupt vector

INT_V

ENDS

 

 

 

;------------------------

Main program---------------------------------------------------------------------------------

 

 

CSEG

 

;

[CODE SEGMENT]

 

 

 

; The stack pointer (SP) and others are assumed to have

 

 

 

 

been initialized.

 

:

 

 

 

 

CLRI

 

;

Disabling interrupts

 

CLRB

TPE

;

Stopping the counter operation

 

MOV

ILR3,#11110111B

;

Setting the interrupt level (level 1)

 

MOV

COMR,#0F4H

;

Comparison value with the counter value (interval)

 

MOV

CNTR,#00101011B

;

Enabling the output of the PWM

 

 

 

; Interval timer operation, selection of 64 tINST

 

 

 

;

Starting the counter operation and enabling the output

 

 

 

 

of interrupt requests

 

SETI

 

;

Enabling interrupts

 

:

 

 

 

;------------------------

Interrupt program----------------------------------------------------------------------------

 

WARI1

CLRB

TIR

;

Clearing the interrupt request flag

 

PUSHW

A

 

 

 

XCHW

A,T

;

Saving A and T

 

PUSHW

A

 

 

157

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Fujitsu F202RA, MB89202 manual Program Example for PWM Timer, Processing specifications
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F202RA, MB89202 specifications

The Fujitsu MB89202 and F202RA microcontrollers are part of the 16-bit microcontroller family, renowned for their robust performance and versatility in a variety of embedded system applications. These devices are tailored for high-efficiency operation across diverse industries, including automotive, consumer electronics, and industrial automation.

One of the main features of the MB89202 is its powerful CPU core, which operates at a clock speed of up to 20 MHz. This enables the microcontroller to perform complex calculations and consumer-grade applications seamlessly. The architecture is designed to handle multiple tasks effectively, making it suitable for real-time operations.

Memory capacity is a vital characteristic of the MB89202, featuring on-chip RAM and ROM configurations. The microcontroller can accommodate different memory variants, providing developers with flexibility in memory allocation based on their application requirements. This adaptability facilitates applications ranging from simple control systems to complex data processing tasks.

The F202RA variant extends the capabilities of the MB89202 by integrating advanced peripheral functions. It includes built-in timers, A/D converters, and serial communication interfaces, which are essential for interfacing with other hardware components or sensors. The availability of these peripherals reduces the need for additional external circuits, thus contributing to a more compact and cost-effective design.

In terms of power management, the MB89202 series employs advanced power-saving technologies. The microcontroller offers various low-power modes, enabling devices to conserve energy during idle times, making it highly suitable for battery-operated applications. This characteristic not only enhances the efficiency of devices but also extends their operational lifespan.

Moreover, the Fujitsu MB89202 series incorporates robust protection features, including watchdog timers and failure detection mechanisms. These safety features ensure reliable operation in critical systems, making them a preferred choice in applications where failure is not an option.

The MB89202 and F202RA microcontrollers also support a range of development tools and environments, including integrated development environments (IDEs) and software libraries, which facilitate rapid application development. With these tools, developers can efficiently prototype, debug, and optimize their applications.

In summary, the Fujitsu MB89202 and F202RA microcontrollers stand out with their efficient performance, extensive memory options, integrated peripherals, and power-saving capabilities, making them ideal for a wide array of embedded applications. Their reliability and robustness further enhance their attractiveness for designers seeking advanced microcontroller solutions.
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