EM78P458/459

OTP ROM

When the A/D conversion is complete, the result is loaded to the ADDATA. The START/END bit is clear, and the ADIF is set.

3. A/D Sampling Time

The accuracy, linearity, and speed of the successive approximation A/D converter are dependent on the properties of the ADC and the comparator. The source impedance and the internal sampling impedance directly affect the time required to charge the sample holding capacitor. The application program controls the length of the sample time to meet the specified accuracy. Generally speaking, the program should wait for 1 μs for each KΩ of the analog source impedance and at least 1 μs for the low-impedance source. After the analog input channel is selected, this acquisition time must be done before the conversion can be started.

4. A/D Conversion Time

CKR0 and CKR1 select the conversion time (Tct), in terms of instruction cycles. This allows the MCU to run at the maximum frequency without sacrificing the accuracy of A/D conversion. For the EM78P458/459, the conversion time per bit is about 4μs. Table 8 shows the relationship between Tct and the maximum operating frequencies.

Table 9 Tct vs. the Maximum Operation Frequency

CKR0:CKR1

Operation Mode

Max. operation frequency

00

Fsco/4

1 MHz

01

Fsco/16

4 MHz

10

Fsco/64

16MHz

11

Internal RC

-

5. A/D Operation During Sleep Mode

In order to reduce power consumption, the A/D conversion remains operational during sleep mode, and is obligated to implement the internal RC clock source mode. As the SLEP instruction is executed, all the operations of the MCU will stop except for the A/D conversion. The RUN bit will be cleared and the result will be fed to the ADDATA when the conversion is completed. If the ADIE is enabled, the device will wake up. Otherwise, the A/D conversion will be shut off, no matter what the status of ADPD bit is.

6.Programming Steps/Considerations

1.Programming steps

Follow these steps to obtain data from the ADC:

This specification is subject to change without prior notice.

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ELAN Home Systems EM78P458, EM78P459AK, EM78P459AM manual D Sampling Time, D Conversion Time, D Operation During Sleep Mode
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EM78P458, EM78P459AM, EM78P458AM, EM78P459AK, EM78P459 specifications

ELAN Home Systems offers a range of advanced microcontrollers, including the EM78P458AP, EM78P459, EM78P459AK, EM78P458AM, and EM78P459AM, that cater to various applications in the consumer electronics sector. These microcontrollers are known for their high efficiency, low power consumption, and robust performance, making them ideal for a wide range of smart home devices.

The EM78P458AP and EM78P459 models feature an 8-bit architecture, enabling efficient processing for applications requiring moderate complexity. They are equipped with a variety of I/O options, including GPIO, UART, and ADC, facilitating seamless integration with numerous peripherals. This flexibility allows developers to create customized solutions tailored to specific user needs.

One of the main highlights of these microcontrollers is their low-power operation, which is essential for battery-operated devices. This is particularly appealing in smart home contexts, where devices are expected to maintain long operational lifetimes without frequent battery replacements. The EM78P458AP and EM78P459 series prioritize energy efficiency, ensuring that they consume minimal power during both active and idle states.

In terms of memory, these microcontrollers also provide substantial ROM and RAM capacities, which enhance their ability to handle complex programs and data. The EM78P459AK variant adds additional features that empower developers with greater flexibility in terms of code storage and execution.

Another critical aspect of these microcontrollers is their built-in protection mechanisms, including voltage and thermal protection, which ensure safe operations under varying environmental conditions. This is vital for home automation systems, where device reliability is paramount to user satisfaction.

The EM78P458AM and EM78P459AM models further extend the family with added functionalities, such as enhanced communication capabilities featuring protocols like I2C and SPI. This facilitates robust inter-device communication, making it easier to integrate various smart home devices into a cohesive network.

Overall, ELAN Home Systems’ EM78P458 and EM78P459 series microcontrollers stand out for their versatile application potential, low power consumption, and reliability. With their innovative technologies and characteristics, they are well-suited for driving the next generation of smart home solutions, ensuring convenience, efficiency, and connectivity for users worldwide.
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