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R01UH0336EJ0102 Rev.1.02
Page 190 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 4 Interrupt Functions
4.5.4
Pending Interrupt Report Function
The state of the currently pending interrupt can be checked with the pending
interrupt report function.
This function allows checking of the following states.
• When interrupts that are masked only by the priority mask function (PMR)
exist
The ICSR.PMF bit is set to 1.
The only case where the ICSR.PMF bit is not set to 1 is when the setting in
the ISPR register is masking interrupts at the given priority level or the
interrupt is masked by settings of the ICxx.MKxx and IMRm.IMRmEIMKn
bits. Thus, the existence of priority requests pended through the priority
mask function can be checked while interrupts are prohibited through
priority masking.
• When EI level maskable interrupt request is not output to the CPU
The ICSR.EIR bit is set to 1.
By looking at the ICSR.EIR bit in the interval during which PSW.ID = 1, it is
possible to check whether an EIINT interrupt request exists.
• When FE level maskable interrupt request is not output to the CPU
ICSR.FIR bit is set to 1.
By looking at the ICSR.FIR bit in the interval during which PSW.NP = 1, it is
possible to check whether a FEINT interrupt request exists.
4.5.5
In-Service Priority Clear Function
This function initializes the internal status of the interrupt controller. It operates
when the ISPC register is accessed. The following operations are possible
using this function.
• Clear all contents of ISPR register
• Clear ICSR.EIE, FIE, and FNE bits
All the bits of ISPR register can be cleared to 0 by writing “1” to all bits of this
register and then writing “0” to all bits of ISPR. Moreover, the ICSR.EIE, FIE,
and FNE bits, which all indicate state in which an interrupt request is being
processed by the CPU core, are all cleared.
The value of the ISPC register is automatically cleared to 0 by writing 0 to all
the bits of ISPR. The values of the bits of ISPR remain unchanged when the
same value is not written to all of the bits.