Z51F6412
Product Specification
PS030302-0212
P R E L I M I N A R Y
51
10.12 Interrupt Register Overview
10.12.1 Interrupt Enable Register (IE, IE1, IE2, IE3, IE4, IE5)
Interrupt enable register consists of Global interrupt control bit (EA) and peripheral interrupt control
bits. Totally 32 peripheral are able to control interrupt.
10.12.2 Interrupt Priority Register (IP, IP1)
The 32 interrupt divides 8 groups which have each 4 interrupt sources. A group can decide 4 levels
interrupt priority using interrupt priority register. Level 3 is the high priority, while level 0 is the low
priority. Initially, IP, IP1 reset value is ‘0’. At that initialization, low interrupt number has a higher
priority than high interrupt number. If decided the priority, low interrupt number has a higher priority
than high interrupt number in that group.
10.12.3 External Interrupt Flag Register (EIFLAG)
The external interrupt flag register is set to ‘1’ when the external interrupt generating condition is
satisfied. The flag is cleared when the interrupt routine is executed. Alternatively, the flag can be
cleared by writing a ‘0’ to it.
10.12.4 External Interrupt Edge Register (EIEDGE)
The External interrupt edge register determines which type of edge or level sensitive interrupt.
Initially, default value is level. For level, write ‘0’ to related bit. For edge, write ‘1’ to related bit.
10.12.5 External Interrupt Polarity Register (EIPOLA)
According to EIEDGE register, the external interrupt polarity (EIPOLA) register has a different
meaning. If EIEDGE is level type, EIPOLA is able to have Low/High level value. If EIEGDE is edge
type, EIPOLA is able to have rising/falling edge value.
10.12.6 External Interrupt Both Edge Enable Register (EIBOTH)
When the external interrupt both edge enable register is written to ‘1’, the corresponding external pin
interrupt is enabled by both edges. Initially, default value is disabled.
10.12.7 External Interrupt Enable Register (EIENAB)
When the external interrupt enable register is written to ‘1’, the corresponding external pin interrupt is
enabled. The EIEDGE and EIPOLA register defines whether the external interrupt is activated on
rising or falling edge or level sensed.