
. . . . .
S Y S T E M C O N T R O L M O D U L E
Vectored interrupt controller (VIC) flow
www.digiembedded.com
151
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V e c t o r e d i n t e r r u p t c o n t r o l l e r ( V I C ) f l o w
This is how the VIC flow works:
1
An interrupt occurs.
2
The CPU branches to either the IRQ or FIQ interrupt vector.
3
If the CPU goes to the IRQ vector, the CPU reads the service routine address from
the VIC’s ISADDR register. The READ updates the VIC’s priority hardware to
prevent current or any lower priority interrupts from interrupting again. The
CPU must not read the ISADDR register for FIQ interrupts.
4
The CPU branches to the Interrupt Service Routine (ISR) and stacks the
workspace so the IRQ can be enabled.
5
The CPU enables the IRQ interrupts so higher priority interrupts can be serviced.
6
The CPU executes the interrupt service routine.
7
The CPU clears the source of the current interrupt.
8
The CPU disables the IRQ and restores the workspace.
9
If IRQ, the CPU writes the level value of the interrupt being serviced to the
ISADDR register to clear the current interrupt path in the VIC’s priority
hardware.
10
The CPU returns from the interrupt.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C o n f i g u r a b l e s y s t e m a t t r i b u t e s
System software can configure these system attributes:
Little endian/big endian mode
Watchdog timer enable
Watchdog timeout generates IRQ/FIQ/RESET
Watchdog timeout interval
Enable/disable ERROR response for misaligned data access
System module clock enables
Enable access to internal registers in USER mode
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
P L L c o n f i g u r a t i o n
Hardware strapping determines the initial powerup PLL (see “Bootstrap
initialization” on page 152). After powerup, software can change the PLL settings
by writing to the PLL Configuration register.
Содержание NS9215
Страница 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Страница 3: ......
Страница 4: ......
Страница 26: ...26 Hardware Reference NS9215...
Страница 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Страница 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Страница 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Страница 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Страница 202: ...S Y S T E M C O N T RO L M OD U L E RTC Module Control register 202 Hardware Reference NS9215...
Страница 260: ...M E MO R Y C O N T ROL L E R StaticMemory Turn Round Delay 0 3 registers 260 Hardware Reference NS9215...
Страница 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Страница 362: ...A E S D AT A E N C R Y P T I O N D E C R Y P T I O N M O D U L E CCM mode 362 Hardware Reference NS9215...
Страница 384: ...I O HU B M OD UL E Module Direct Mode TX Data Last FIFO 384 Hardware Reference NS9215 31 March 2008...
Страница 414: ...S E R I A L C ON T RO L M O D U L E U ART UART Modem Status register 414 Hardware Reference NS9215...
Страница 446: ...S E R I A L C ON T RO L M O D U L E S PI SPI timing characteristics 446 Hardware Reference NS9215...
Страница 472: ...R E A L TI M E C L O C K M O D U L E General Status register 472 Hardware Reference NS9215...
Страница 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Страница 514: ...PA CKA GING Processor Dimensions 514 Hardware Reference NS9215 P r o c e s s o r D i m e n s i o n s...
Страница 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Страница 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...