Datasheet
Section 5 Interrupt Controller
Rev.6.00 Sep. 27, 2007 Page 118 of 1268
REJ09B0220-0600
5.2.5 IRQ Status Register (ISR)
Bit : 7 6 5 4 3 2 1 0
IRQ7F IRQ6F IRQ5F IRQ4F IRQ3F IRQ2F IRQ1F IRQ0F
Initial value : 0 0 0 0 0 0 0 0
R/W : R/(W)
*
R/(W)
*
R/(W)
*
R/(W)
*
R/(W)
*
R/(W)
*
R/(W)
*
R/(W)
*
Note: * Only 0 can be written, to clear the flag.
ISR is an 8-bit readable/writable register that indicates the status of IRQ7 to IRQ0 interrupt
requests.
ISR is initialized to H'00 by a reset and in hardware standby mode.
Bits 7 to 0—IRQ7 to IRQ0 flags (IRQ7F to IRQ0F): These bits indicate the status of IRQ7 to
IRQ0 interrupt requests.
Bit n
IRQnF
Description
0 [Clearing conditions] (Initial value)
• Cleared by reading IRQnF flag when IRQnF = 1, then writing 0 to IRQnF flag
• When interrupt exception handling is executed when low-level detection is set
(IRQnSCB = IRQnSCA = 0) and IRQn input is high
• When IRQn interrupt exception handling is executed when falling, rising, or both-
edge detection is set (IRQnSCB = 1 or IRQnSCA = 1)
• When the DTC is activated by an IRQn interrupt, and the DISEL bit in MRB of the
DTC is cleared to 0
1 [Setting conditions]
• When IRQn input goes low when low-level detection is set (IRQnSCB = IRQnSCA =
0)
• When a falling edge occurs in IRQn input when falling edge detection is set
(IRQnSCB = 0, IRQnSCA = 1)
• When a rising edge occurs in IRQn input when rising edge detection is set
(IRQnSCB = 1, IRQnSCA = 0)
• When a falling or rising edge occurs in IRQn input when both-edge detection is set
(IRQnSCB = IRQnSCA = 1)
(n = 7 to 0)