HT45F3820 Datasheet, PDF (98/121 Pages) Holtek Semiconductor Inc – Ultrasonic Atomizer Flash MCU

HT45F3820
Ultrasonic Atomizer Flash MCU
OCVP Interrupt
An OCVP interrupt request will take place when the OCVP Interrupt request flag, OCVPF, is set,
which occurs when the OCVP circuit detects a specific current or voltage condition. To allow the
program to branch to its respective interrupt vector address, the global interrupt enable bit, EMI,
and the OCVP Interrupt enable bit, OCVPE, must first be set. When the interrupt is enabled, the
stack is not full and a user-defined current or voltage condition occurs, a subroutine call to the
OCVP Interrupt vector, will take place. When the OCVP Interrupt is serviced, the EMI bit will be
automatically cleared to disable other interrupts and the OCVP interrupt request flag will be also
automatically cleared.
Multi-function Interrupts
Within the device there are three Multi-function interrupts. Unlike the other independent interrupts,
these interrupts have no independent source, but rather are formed from other existing interrupt
sources, namely the TM Interrupts, LVD Interrupt and EEPROM Interrupt.
A Multi-function interrupt request will take place when any of the Multi-function interrupt request
flags, MFnF are set. The Multi-function interrupt flags will be set when any of their included
functions generate an interrupt request flag. To allow the program to branch to its respective interrupt
vector address, when the Multi-function interrupt is enabled and the stack is not full, and either one
of the interrupts contained within each of Multi-function interrupt occurs, a subroutine call to one of
the Multi-function interrupt vectors will take place. When the interrupt is serviced, the related Multi-
Function request flag, will be automatically reset and the EMI bit will be automatically cleared to
disable other interrupts.
However, it must be noted that, although the Multi-function Interrupt flags will be automatically
reset when the interrupt is serviced, the request flags from the original source of the Multi-
function interrupts, namely the TM Interrupts, LVD Interrupt and EEPROM Interrupt will not be
automatically reset and must be manually reset by the application program.
Time Base Interrupts
The function of the Time Base interrupts is to provide regular time signal in the form of an internal
interrupt. They are controlled by the overflow signals from their respective timer functions. When
these happens their respective interrupt request flags, TB0F or TB1F will be set. To allow the
program to branch to their respective interrupt vector addresses, the global interrupt enable bit, EMI
and Time Base enable bits, TB0E or TB1E, must first be set. When the interrupt is enabled, the stack
is not full and the Time Base overflows, a subroutine call to their respective vector locations will
take place. When the interrupt is serviced, the respective interrupt request flag, TB0F or TB1F, will
be automatically reset and the EMI bit will be cleared to disable other interrupts.
The purpose of the Time Base Interrupt is to provide an interrupt signal at fixed time periods. Their
clock sources originate from the internal clock source fTB. This fTB input clock passes through a
divider, the division ratio of which is selected by programming the appropriate bits in the TBC
register to obtain longer interrupt periods whose value ranges. The clock source that generates fTB,
which in turn controls the Time Base interrupt period, can originate from several different sources
which is selected using the TBCK bit in the TBC register.
Rev. 1.11
98
April 11, 2017