EM78P458/459

 

 

 

 

OTP ROM

 

 

 

 

 

 

 

Table 4 Usage of Port 6 Input Changed Wake-up/Interrupt Function

 

 

 

 

 

 

 

 

Usage of Port 6 Input Status Changed Wake-up/Interrupt

 

 

 

 

 

 

 

 

(I) Wake-up from Port 6 Input Status Change

(II) Port 6 Input Status Change Interrupt

 

 

(a) Before SLEEP

1.

Read I/O Port 6 (MOV R6,R6)

 

 

1.

Disable WDT

2.

Execute "ENI"

 

 

2.

Read I/O Port 6 (MOV R6,R6)

3.

Enable interrupt (Set IOCF0.1)

 

 

3.

Execute "ENI" or "DISI"

4.

IF Port 6 changed (interrupt)

 

 

4.

Enable interrupt (Set IOCF0.1)

 

→ Interrupt vector (008H)

 

 

5.

Execute "SLEP" instruction

 

 

 

 

 

(b) After wake-up

 

 

 

 

 

1.

IF "ENI" → Interrupt vector (008H)

 

 

 

 

 

2.

IF "DISI" → Next instruction

 

 

 

 

4.5 RESET and Wake-up

1. The function of RESET and Wake-up

A RESET is initiated by one of the following events-

(1)Power-on reset

(2)/RESET pin input "low", or

(3)WDT time-out (if enabled).

The device is kept in a RESET condition for a period of approximately 18ms (one oscillator start-up timer period) after the reset is detected. Once the RESET occurs, the following functions are performed.

•The oscillator is running, or will be started.

•The Program Counter (R2) is set to all "0".

•All I/O port pins are configured as input mode (high-impedance state).

•The Watchdog Timer and prescaler are cleared.

•When power is switched on, the upper 3 bits of R3 are cleared.

•The bits of the CONT register are set to all "1" except for the Bit 6 (INT flag).

•The bits of the IOCB0 register are set to all "1".

•The IOCC0 register is cleared.

•The bits of the IOCD0 register are set to all "1".

•Bit 7 of the IOCE0 register is set to "1", and Bit 6 is cleared.

•Bits 0~6 of RF register and bits 0~6 of IOCF0 register are cleared.

Executing the “SLEP” instruction will assert the sleep (power down) mode. While entering sleep mode, the WDT (if enabled) is cleared but keeps on running. The controller can be awakened by-

This specification is subject to change without prior notice.

26

07.01.2003 (V1.3)

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ELAN Home Systems EM78P458AM Function of Reset and Wake-up, Usage of Port 6 Input Changed Wake-up/Interrupt Function
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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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