mc68hc912dg128 Freescale Semiconductor, Inc, mc68hc912dg128 Datasheet - Page 138

• Manufacturer Part Number: mc68hc912dg128
• Description: M68hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Resets and Interrupts
HPRIO — Highest Priority I Interrupt
9.6 Interrupt test registers
Technical Data
138
RESET:
Bit 7
1
1
PSEL6
6
1
Write only if I mask in CCR = 1 (interrupts inhibited). Read anytime.
To give a maskable interrupt source highest priority, write the low byte of
the vector address to the HPRIO register. For example, writing $F0 to
HPRIO would assign highest maskable interrupt priority to the real-time
interrupt timer ($FFF0). If an un-implemented vector address or a non-I-
masked vector address (value higher than $F2) is written, then IRQ will
be the default highest priority interrupt.
These registers are used in special modes for testing the interrupt logic
and priority without needing to know which modules and what functions
are used to generate the interrupts.Each bit is used to force a specific
interrupt vector by writing it to 1.Bits are named with B6 through F4 to
indicate vectors $FFB6 through $FFF4. These bits are also used in
special modes to view that an interrupt caused by a module has reached
the interrupt module.
These registers can only be read in special modes (read in normal mode
will return $00). Reading these registers at the same time as the interrupt
is changing will cause an indeterminate value to be read. These
registers can only be written in special mode.
Freescale Semiconductor, Inc.
For More Information On This Product,
PSEL5
5
1
Go to: www.freescale.com
Resets and Interrupts
PSEL4
4
1
PSEL3
3
0
PSEL2
2
0
PSEL1
MC68HC912DG128 — Rev 3.0
1
1
Bit 0
0
0
MOTOROLA
$001F