EM78P458/459

OTP ROM

4.6 Interrupt

The EM78P458/459 has six interrupts as listed below:

(1)TCC overflow interrupt

(2)Port 6 Input Status Change Interrupt

(3)External interrupt [(P50, /INT) pin].

(4)Analog to Digital conversion completed.

(5)When TMR1/TMR2 matches with PRD1/PRD2 respectively in PWM.

(6)When the comparators output change.

Before the Port 6 Input Status Change Interrupt is enabled, reading Port 6 (e.g. "MOV R6,R6") is necessary. Each Port 6 pin will have this feature if its status changes. Any pin configured as output or P50 pin configured as /INT, is excluded from this function. Port 6 Input Status Change Interrupt will wake up the EM78P458/459 from the sleep mode if it is enabled prior to going into the sleep mode by executing SLEP. When the controller is wake-up, it will continue to execute the succeeding program if the global interrupt is disabled, or branches out to the interrupt vector 008H if the global interrupt is enabled.

RF, the interrupt status register that records the interrupt requests in the relative flags/bits. IOCF0 is an interrupt mask register. The global interrupt is enabled by the ENI instruction and is disabled by the DISI instruction. When one of the interrupts (when enabled) occurs, the next instruction will be fetched from address 008H. Once in the interrupt service routine, the source of an interrupt can be determined by polling the flag bits in RF. The interrupt flag bit must be cleared by instructions before leaving the interrupt service routine to avoid recursive interrupts.

The flag (except ICIF bit) in the Interrupt Status Register (RF) is set regardless of the status of its mask bit or the execution of ENI. Note that the outcome of RF will be the logic AND of RF and IOCF0 (refer to Fig. 11). The RETI instruction ends the interrupt routine and enables the global interrupt (the execution of ENI).

When an interrupt is generated by the INT instruction (when enabled), the next instruction will be fetched from address 001H.

This specification is subject to change without prior notice.

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ELAN Home Systems EM78P459AK, EM78P459AM, EM78P458AM, EM78P458AP manual Interrupt
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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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