
Resets and Interrupts
Reset and Interrupt Priority
MC68HC11E Family
—
Rev. 4
Technical Data
MOTOROLA
Resets and Interrupts
119
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.
5.5.1 Highest Priority Interrupt and Miscellaneous Register
RBOOT
—
Read Bootstrap ROM Bit
Has meaning only when the SMOD bit is a 1 (bootstrap mode or
special test mode). At all other times this bit is clear and cannot be
written. Refer to
Section 4. Operating Modes and On-Chip Memory
for more information.
SMOD
—
Special Mode Select Bit
This bit reflects the inverse of the MODB input pin at the rising edge
of reset. Refer to
Section 4. Operating Modes and On-Chip
Memory
for more information.
Address:
$103C
Bit 7
6
5
4
3
2
1
Bit 0
Read:
RBOOT
(1)
SMOD
(1)
MDA
(1)
IRVNE
PSEL2
PSEL2
PSEL1
PSEL0
Write:
Reset:
Single chip:
0
0
0
0
0
1
1
0
Expanded:
0
0
1
0
0
1
1
0
Bootstrap:
1
1
0
0
0
1
1
0
Special test:
0
1
1
1
0
1
1
0
1. The values of the RBOOT, SMOD, and MDA reset bits depend on the mode selected at the
RESET pin rising edge. Refer to
Table 4-1. Hardware Mode Select Summary
.
Figure 5-4. Highest Priority I-Bit Interrupt
and Miscellaneous Register (HPRIO)