Am186™CC/CH/CU Microcontrollers User’s Manual
7-1
CHAPTER
7
INTERRUPTS
7.1
OVERVIEW
An interrupt is a request to the CPU for service. CPUs receive interrupt requests from a
variety of sources, both internal and external. When the CPU receives a request, it stops
executing the current task, and if the new task is of higher priority, begins executing that
routine. At the end of the routine, the CPU returns to the original task.
Some interrupts can be disabled. These are called
maskable interrupts. Nonmaskable
interrupts cannot be disabled.
The Am186CC/CH/CU microcontrollers feature an interrupt controller, which arranges the
maskable interrupt requests by priority and presents them one at a time to the CPU. In
addition to interrupts managed by the interrupt controller, the microcontroller supports eight
nonmaskable interrupts—an external or internal nonmaskable interrupt (NMI), a trace
interrupt, and software interrupts and exceptions.
The interrupt controller supports the maskable interrupt sources through the use of 15
channels. To make this possible, most interrupt channels support multiple interrupt sources.
These channels are programmable to support the external interrupt pins or various
peripheral devices that can be configured to generate interrupts. The maskable interrupt
sources include 17 external sources plus a number of internal sources.
The Am186CC microcontroller has 19 internal maskable interrupt sources.
The Am186CH HDLC microcontroller has 14 internal maskable interrupt sources.
The Am186CU USB microcontroller has 13 internal maskable interrupt sources.
The following Am186CC microcontroller peripherals can generate internal interrupts:
■
Three on-board timers (two of the timers can operate as pulse width modulators)
■
Two UARTs
■
Four HDLC channels
■
The GCI
■
Four pairs of transmit/receive SmartDMA channels
■
Four general-purpose DMA channels
■
The USB peripheral controller
CC
CH
CU
CC
Содержание Am186 CC
Страница 1: ...Am186 CC CH CU Microcontrollers User s Manual Order 21914B...
Страница 4: ...iv Am186 CC CH CU Microcontrollers User s Manual...
Страница 18: ...Table of Contents xviii Am186 CC CH CU Microcontrollers User s Manual...
Страница 24: ...Introduction xxiv Am186 CC CH CU Microcontrollers User s Manual...
Страница 39: ...Architectural Overview Am186 CC CH CU Microcontrollers User s Manual 1 15 Figure 1 6 32 Channel Linecard CH CC...
Страница 40: ...Architectural Overview 1 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 86: ...System Overview 3 36 Am186 CC CH CU Microcontrollers User s Manual...
Страница 92: ...Emulator Support 4 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 112: ...DRAM Controller 6 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 134: ...Interrupts 7 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 186: ...Programmable I O Signals 9 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 200: ...Watchdog Timer 11 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 232: ...Asynchronous Serial Ports UARTs 13 24 Am186 CC CH CU Microcontrollers User s Manual...
Страница 242: ...Synchronous Serial Port SSI 14 10 Am186 CC CH CU Microcontrollers User s Manual...
Страница 264: ...High Level Data Link Control HDLC 15 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 332: ...Universal Serial Bus USB 18 34 Am186 CC CH CU Microcontrollers User s Manual...
Страница 348: ...Register Summary A 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 376: ...Index Index 18 Am186 CC CH CU Microcontrollers User s Manual...