CHAPTER 12 A/D CONVERTER

Figure 12.6-2 Setting A/D Conversion Functions (at Continuous Activation)

ADC1

ADC2

ADDH

bit7 bit6

bit5

bit4

bit3

bit2

bit1

bit0

 

 

 

ANS2

ANS1

ANS0

ADI

ADMV

RESV0

AD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RESV4

 

RESV3

ADCK

ADIE

RESV2

EXT

RESV1

 

 

 

0

 

0

 

 

0

1

1

The results of A/D conversion are stored.

ADDL

The results of A/D conversion are stored.

ADEN

: Used bit

: Unused bit

1: Set "1"

0: Set "0"

: Set "1" to an appropriate bit

When continuous activation is enabled, A/D conversion is activated on a rising edge of the selected input clock and the operations of A/D conversion functions are started. When continuous activation is disabled (ADC2: EXT = 0), continuous activation is stopped and activation with software is possible.

■Operations of A/D Conversion Functions

The operations of the A/D converter are described here. It takes about 38 instruction cycles from activating A/D conversion to completing it.

1.When A/D conversion is activated, the conversion in-progress flag bit is set (ADC1: ADMV = 1), and the analog input set is connected to the sample hold circuit.

2.During about 16 instruction cycles, the voltage of the analog input is captured and held in the capacitor for internal sample hold. This voltage is held until A/D conversion has been completed.

3.The comparator compares the voltage captured and held in the capacitor for sample hold with the reference voltage for A/D conversion from the MSB to the LSB. The results are transferred to the ADDH and ADDL registers in turn.

4.When all the results have been transferred to the ADDH and ADDL registers, the conversion in- progress flag bit is cleared (ADC1: ADMV = 0), and the interrupt request flag bit is set (ADC1: ADI = 1).

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Fujitsu MB89202, F202RA manual Operations of A/D Conversion Functions, 274
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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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