Filter
Top Products
316
Chapter 24 Interrupt Control
4.Registers
ICR (Interrupt Control Register) is a register in the interrupt controller, and it specifies the interrupt level for
each interrupt request. ICR corresponds to each of interrupt request input. ICR is mapped to the I/O space.
• ICR00 – ICR63
(About attributes, see “Meaning of Bit Attribute Symbols (Page No.10)”.)
• Bit 7-5: Undefined. Writing does not affect the operation. The read value is indeterminate.
• Bit 4-0: Interrupt level setting bits
• The interrupt level setting bit specifies the interrupt level of the corresponding interrupt request.
• When the interrupt level set to the interrupt control register is the same as, or higher than the level mask
value set to the ILM register of the CPU, the interrupt request is masked by the CPU side.
76543210bit
– – – ICR4 ICR3 ICR2 ICR1 ICR0
–––11111
Initial
value
RX/WX RX/WX RX/WX R/WX R/W R/W R/W R/W Attribute
ICR4-ICR0 bits Interrupt level Description
0000-01110 0-14 Reserved for system (cannot to be set)
01111 15 NMI
10000 16 The highest level
10001 17 (High)
10010 18
10011 19
10100 20
10101 21
10110 22
10111 23
11000 24
11001 25
11010 26
11011 27
11100 28
11101 29 (Low)
11110 30 The lowest level
11111 31 Disable interrupts