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Otp rom, 2 special purpose registers – ELAN Home Systems EM78P458 User Manual

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EM78P458/459

OTP ROM

An 8-bit general-purpose register.

13. RE

A 2-bit, Bit 0 and Bit 1 register.

14. RF (Interrupt Status Register)

7

6

5

4

3

2

1

0

- CMPIF

PWM2IF

PWM1IF

ADIF EXIF ICIF TCIF

“1” means interrupt request, and “0” means no interrupt occurs.

Bit 0 (TCIF) TCC overflow interrupt flag. Set when TCC overflows, reset by software.

Bit 1 (ICIF) Port 6 input status change interrupt flag. Set when Port 6 input changes, reset by

software.

Bit 2 (EXIF) External interrupt flag. Set by falling edge on /INT pin, reset by software.

Bit 3 (ADIF) Interrupt flag for analog to digital conversion. Set when AD conversion is completed,

reset by software.

Bit 4 (PWM1IF) PWM1 (Pulse Width Modulation) interrupt flag. Set when a selected period is

reached, reset by software.

Bit 5 (PWM2IF) PWM2 (Pulse Width Modulation) interrupt flag. Set when a selected period is

reached, reset by software.

Bit 6 (CMPIF) High-compared interrupt flag. Set when a change occurs in the output of Comparator,

reset by software.

Bit 7 Unemployed, read as ‘0’;

• RF can be cleared by instruction but cannot be set.

• IOCF0 is the interrupt mask register.

• Note that to read RF will result to "logic AND" of RF and IOCF0.

15. R10 ~ R3F

• All of these are 8-bit general-purpose registers.

4.2 Special Purpose Registers

1. A (Accumulator)

• Internal data transfer, or instruction operand holding

• It can not be addressed.

This specification is subject to change without prior notice. 07.01.2003 (V1.3)

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