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MSM66573 Family User's Manual
Chapter 16 Interrupt Processing Functions
16
16.3.2 Maskable Interrupts
Maskable interrupts are generated by various interrupt factors such as built-in internal
peripheral hardware, external interrupt inputs, etc.
The control of maskable interrupts is performed by the following.
Interrupt request registers (IRQ0 to IRQ4)
Interrupt enable registers (IE0 to IE4)
Master interrupt enable flag (MIE)
Master interrupt priority flag (MIPF)
Interrupt priority control registers (IP0 to IP9)
(1)
Interrupt request registers (IRQ0 to IRQ4)
Interrupt request registers (IRQs) are set to "1" when each interrupt source generates an
interrupt signal. If an interrupt is received, the registers are automatically reset to "0" while
transferring to the interrupt processing routine. IRQ bits can also be set to "1" or "0" by the
program.
(2)
Interrupt enable registers (IE0 to IE4)
Interrupt enable registers (IEs) individually enable or disable the generation of interrupts.
When an IE bit is "0", generation of the corresponding interrupt is disabled. When an IE bit
is "1", generation of the corresponding interrupt is enabled.
(3)
Master interrupt enable flag (MIE)
The master interrupt enable flag (MIE) is a 1-bit flag located in the program status word
(PSW). MIE enables or disables generation of all the maskable interrupts.
MIE = "0" All maskable interrupts are disabled (regardless of IE)
MIE = "1" Maskable interrupts are enabled (only those interrupt factors enabled by IE)
[Related information reference guide]
Program status word (PSW) … Page 2-17
(4)
Master interrupt priority flag (MIPF)
The master interrupt priority flag (MIPF) is a 1-bit flag located in the external interrupt control
register 2 (EXI2CON). MIPF enables or disables priority for all the maskable interrupts.
MIPF = "0" Priority control disabled (regardless of IP, interrupts controlled by MIE and IE
only)
MIPF = "1" Priority control enabled (3 levels of priority control according to IP setting)
[Related information reference guide]
External interrupt control register 2 (EXI2CON) … Page 15-4