
Interrupt Control Unit
7-9
7.1.6
Interrupt Controller Reset Conditions
On reset, the interrupt controller performs the following nine actions:
1. All special fully nested mode (SFNM) bits are reset, implying fully nested mode.
2. All priority (PR) bits in the various control registers are set to 1. This places all sources
at the lowest priority (level 7).
3. All level-triggered mode (LTM) bits are reset to 0, resulting in edge-triggered mode.
4. All interrupt in-service bits are reset to 0.
5. All interrupt request bits are reset to 0.
6. All mask (MSK) bits are set to 1. All interrupts are masked.
7. All cascade (C) bits are reset to 0 (non-cascade).
8. The interrupt priority mask is set to 7, allowing interrupts of all priorities.
9. The interrupt controller is initialized to master mode.
Summary of Contents for Am186 ES
Page 1: ...Am186 ES and Am188 ES User s Manual...
Page 4: ...iv...
Page 12: ...Table of Contents xii...
Page 22: ...Features and Performance 1 8...
Page 60: ...System Overview 3 28...
Page 84: ...Chip Select Unit 5 14...
Page 132: ...Timer Control Unit 8 8...
Page 166: ...Programmable I O Pins 11 6...
Page 184: ...Register Summary A 18...