5.2.3 IRQ Status Register (ISR)
ISR is an 8-bit readable/writable register that indicates the status of IRQ
0
to IRQ
5
interrupt
requests.
ISR is initialized to H'00 by a reset and in hardware standby mode.
Bits 7 and 6—Reserved: Read-only bits, always read as 0.
Bits 5 to 0—IRQ
5
to IRQ
0
Flags (IRQ
5
F to IRQ
0
F): These bits indicate the status of
IRQ
5
to IRQ
0
interrupt requests.
Bits 5 to 0
IRQ5F to IRQ0F
Description
0
[Clearing conditions]
(Initial value)
0 is written in IRQnF after reading the IRQnF flag when IRQnF = 1.
IRQnSC = 0, IRQn input is high, and interrupt exception handling is carried out.
IRQnSC = 1 and IRQn interrupt exception handling is carried out.
1
[Setting conditions]
IRQnSC = 0 and IRQn input is low.
IRQnSC = 1 and IRQn input changes from high to low.
Note: n = 5 to 0
Bit
Initial value
Read/Write
7
—
0
—
These bits indicate IRQ to IRQ
interrupt request status
Note: Only 0 can be written, to clear flags.
*
6
—
0
—
5
IRQ5F
0
R/(W)
*
4
IRQ4F
0
R/(W)
*
3
IRQ3F
0
R/(W)
*
2
IRQ2F
0
R/(W)
*
1
IRQ1F
0
R/(W)
*
0
IRQ0F
0
R/(W)
*
5
0
IRQ to IRQ flags
5
0
Reserved bits
92
www.DataSheet4U.com