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MC68HC11D3
RESETS AND INTERRUPTS
MOTOROLA
TECHNICAL DATA
5-7
The maskable interrupt sources have the following priority arrangement:
1. IRQ
2. Real-time interrupt
3. Timer input capture 1
4. Timer input capture 2
5. Timer input capture 3
6. Timer output compare 1
7. Timer output compare 2
8. Timer output compare 3
9. Timer output compare 4
10. Timer input capture 4/output compare 5
11. Timer overflow
12. Pulse accumulator overflow
13. Pulse accumulator input edge
14. SPI transfer complete
15. SCI system
Any one of these interrupts can be assigned the highest maskable interrupt priority by
writing the appropriate value to the PSEL bits in the HPRIO register. Otherwise, the
priority arrangement remains the same. An interrupt that is assigned highest priority is
still subject to global masking by the I bit in the CCR, or by any associated local bits.
Interrupt vectors are not affected by priority assignment. To avoid race conditions,
HPRIO can be written only while I-bit interrupts are inhibited.
5.3.1 Highest Priority Interrupt and Miscellaneous Register
The values of the RBOOT, SMOD, IRVNE, and MDA reset bits depend on the mode
RBOOT — Read Bootstrap ROM
Has meaning only when the SMOD bit is a one (special bootstrap mode or special test
mode). At all other times this bit is clear and cannot be written. Refer to SECTION 4 SMOD — Special Mode Select
This bit reflects the inverse of the MODB input pin at the rising edge of reset. Refer to
MDA — Mode Select A
The mode select A bit reflects the status of the MODA input pin at the rising edge of
information.
IRVNE — Internal Read Visibility Enable/Not E
HPRIO — Highest Priority I-Bit Interrupt and Miscellaneous
$003C
Bit 7
654321
Bit 0
RBOOT
SMOD
MDA
IRVNE
PSEL3
PSEL2
PSEL1
PSEL0
RESET:
—
0101