External Interrupt; Multi-Function Interrupt; A/D Converter Interrupt - Holtek HT67F2350 Manual

HT67F2350/HT67F2360
HT67F2370/HT67F2390
Advanced A/D Flash MCU with LCD & EEPROM

External Interrupt

The external interrupts are controlled
interrupt request will take place when the external interrupt request flags, INT0F~INT3F, are set,
which will occur when a transition, whose type is chosen by the edge select bits, appears on the
external interrupt pins. To allow the program to branch to its respective interrupt vector address,
the global interrupt enable bit, EMI, and respective external interrupt enable bit, INT0E~INT3E,
must first be set. Additionally the correct interrupt edge type must be selected using the INTEG
register to enable the external interrupt function and to choose the trigger edge type. As the external
interrupt pins are pin-shared with I/O pins, they can only be configured as external interrupt pins if
their external interrupt enable bit in the corresponding interrupt register has been set and the external
interrupt pin is selected by the corresponding pin-shared function selection bits. The pin must also
be setup as an input by setting the corresponding bit in the port control register. When the interrupt
is enabled, the stack is not full and the correct transition type appears on the external interrupt pin,
a subroutine call to the external interrupt vector, will take place. When the interrupt is serviced, the
external interrupt request flags, INT0F~INT3F, will be automatically reset and the EMI bit will be
automatically cleared to disable other interrupts. Note that any pull-high resistor selections on the
external interrupt pins will remain valid even if the pin is used as an external interrupt input.
The INTEG register is used to select the type of active edge that will trigger the external interrupt.
A choice of either rising or falling or both edge types can be chosen to trigger an external interrupt.
Note that the INTEG register can also be used to disable the external interrupt function.

Multi-function Interrupt

Within the device there are up to ten 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, EEPROM write operation interrupt,
SIM interface interrupt, SPIA interface interrupt, UART interface interrupts, Comparator interrupts
and Time Base interrupts.
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 request flags will be
automatically reset when the interrupt is serviced, the request flags from the original source of
the Multi-function interrupts will not be automatically reset and must be manually reset by the
application program.

A/D Converter Interrupt

The A/D Converter Interrupt is controlled by the termination of an A/D conversion process. An A/D
Converter Interrupt request will take place when the A/D Converter Interrupt request flag, ADF, is
set, which occurs when the A/D conversion process finishes. To allow the program to branch to its
respective interrupt vector address, the global interrupt enable bit, EMI, and A/D Interrupt enable bit,
ADE, must first be set. When the interrupt is enabled, the stack is not full and the A/D conversion
process has ended, a subroutine call to the A/D Converter Interrupt vector, will take place. When the
interrupt is serviced, the A/D Converter Interrupt flag, ADF, will be automatically cleared. The EMI
bit will also be automatically cleared to disable other interrupts.
Rev. 1.60
by signal transitions on the pins INT0~INT3. An external
259 May 16, 2019