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Chapter 25 External Interrupt
4.Registers
4. Registers
4.1 ELVR: Interrupt Request Level Register
The register that selects request detection of external interrupts.
• ELVR0 (INT0-INT7): Address 032H (access: Half-word, Word)
(About attributes, see “Meaning of Bit Attribute Symbols (Page No.10)”.)
• ELVR1 (INT8-INT15): Address 036H (access: Half-word, Word)
(About attributes, see “Meaning of Bit Attribute Symbols (Page No.10)”.)
Interrupt request level bits (LBn, LAn) are registers that select request detection.
2 bits (LBn, LAn) are assigned to each external interrupt INTn.
When the request input is a level (LAn, LBn = “00” or “01”), and when the INTn pin input is the valid level, the
corresponding bit (ERn) will be re-set to “1” even if the external interrupt request bit (ERn) is set to “0”.
Note: n = 0 to 15
15 14 13 12 11 10 9 8 Bit
LB7 LA7 LB6 LA6 LB5 LA5 LB4 LA4
00000000Initial value
R/W R/W R/W R/W R/W R/W R/W R/W Attribute
76543210 Bit
LB3 LA3 LB2 LA2 LB1 LA1 LB0 LA0
00000000Initial value
R/W R/W R/W R/W R/W R/W R/W R/W Attribute
15 14 13 12 11 10 9 8 Bit
LB15 LA15 LB14 LA14 LB13 LA13 LB12 LA12
00000000Initial value
R/W R/W R/W R/W R/W R/W R/W R/W Attribute
76543210 Bit
LB11 LA11 LB10 LA10 LB9 LA9 LB8 LA8
00000000Initial value
R/W R/W R/W R/W R/W R/W R/W R/W Attribute
LBn LAn Description
0 0 Detect “L” level and generate an interrupt request.
0 1 Detect “H” level and generate an interrupt request.
1 0 Detect the rise and generate an interrupt request.
1 1 Detect the fall and generate an interrupt request.
