M16C30P Datasheet, PDF (16/57 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/30P Group
2. Central Processing Unit (CPU)
2.8.8 Stack Pointer Select Flag (U Flag)
ISP is selected when the U flag is “0”; USP is selected when the U flag is “1”.
The U flag is cleared to “0” when a hardware interrupt request is accepted or an INT instruction for software
interrupt Nos. 0 to 31 is executed.
2.8.9 Processor Interrupt Priority Level (IPL)
IPL is configured with three bits, for specification of up to eight processor interrupt priority levels from level 0
to level 7.
If a requested interrupt has priority greater than IPL, the interrupt is enabled.
2.8.10 Reserved Area
When write to this bit, write “0”. When read, its content is indeterminate.
Rev.1.22 Mar 30, 2007 Page 16 of 53
REJ03B0088-0122