EM78P458/459

OTP ROM

4.3 TCC/WDT & Prescaler

An 8-bit counter is available as prescaler for the TCC or WDT. The prescaler is available for either the TCC or WDT only at any given time, and the PAB bit of CONT register is used to determine the prescaler assignment. The PSR0~PSR2 bits determine the prescale ratio. The prescaler is cleared each time the instruction is written to TCC under TCC mode. The WDT and prescaler, when assigned to WDT mode, are cleared by the WDTC or SLEP instructions. Fig. 5 depicts the circuit diagram of TCC/WDT.

•R1(TCC) is an 8-bit timer/counter. The TCC clock source can be internal or external clock input (edge selectable from TCC pin). If TCC signal source is from internal clock, TCC will increase by 1 at every instruction cycle (without prescaler). Referring to Fig. 5, selection of CLK=Fosc/2 or CLK=Fosc/4 depends on the CODE Option bit CLKS. CLK=Fosc/2 if CLKS bit is "0", and CLK=Fosc/4 if CLKS bit is "1".

•If TCC signal source is from external clock input, TCC will increase by 1 at every falling edge or rising edge of TCC pin.

•The watchdog timer is a free running on-chip RC oscillator. The WDT will keep on running even after the oscillator driver has been turned off (i.e. in sleep mode). During normal operation or sleep mode, a WDT time-out (if enabled) will cause the device to reset. The WDT can be enabled or disabled at any time during the normal mode by software programming. Refer to WDTE bit of IOCE0 register. Without presacler, the WDT time-out period is approximately 18 ms1.

1NOTE: VDD=5V,Setup time period = 16ms ± 5%.

VDD=3V,Setup time period = 19ms ± 5%.

This specification is subject to change without prior notice.

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07.01.2003 (V1.3)

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ELAN Home Systems EM78P459AK, EM78P459AM, EM78P458AM, EM78P458AP manual TCC/WDT & Prescaler
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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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