timer0.1.2.3_interrupt_doc.txt

包含了NXP众多的MCU的例子程序

This example shows a "bare bones" program to set up an interrupt on Timer0 match compare on
channel 0, and how to install the ISR, and configure the VIC for it to interrupt as an IRQ.

Specifications:
1. Configure Timer0 to interrupt on matching value 3,680 in MR0, generating 100Hz intrpt rate.
1. Configure Timer1 to interrupt on matching value 3,680 in MR0, generating 143Hz intrpt rate.
1. Configure Timer0 to interrupt on matching value 3,680 in MR0, generating 91Hz intrpt rate.
1. Configure Timer0 to interrupt on matching value 3,680 in MR0, generating 333Hz intrpt rate.
2. Set up IRQ isrs to execute directly, this requires instruction at address 0x18
   to be ldr pc,[pc,#-0xFF0]. ISRs must be written in ARM mode and have __irq
   keyword in declaration and definition
3. increment a counter in timer isr
4. when counter in isr = limit for various interrupts, set a bit in bl_TmrFlag so foreground loop
   knows which port pin to toggle
5. clear bit in Tmr0_Flag in foreground loop that was set by isr
6. Toggle the state of port pins blink LED6 on row of LEDs
7. Do not make provision for nesting of interrupts, timer interrupt is higher priority than
   EXTINT1 and EXTINT2. If EXTINT1 or EXTINT22 happens while timer isr is executing, it will
   PEND.
8. Application should run out of flash or RAM
9. Ensure that PLL is disengaged by clearing PLLE and PLLC and giving PLL feed
   sequence
11.Use .ddf file iolpc2103MM.ddf instead of iolpc2103.ddf which is provided as
   as a default when the LPC2103 part is chosen in Project\Options\General.
   This is because displaying the register VICVectAddr in C-SPY debugger's
   register window can affect the state machine og the VIC, and under certain
   circumstances disable interrupts. If the content of VICVectAddr must be
   known, copy it into a register at read time for later display.
12.Handle undefined instruction, instruction prefetch and data abort with a C function handler
   that spins in a while(1) loop.

Author: Mark Moran

Last Date Modified: 6 Jan  2006
Status:
- Works as specified exectuing out of RAM
- Works as specified executing out of flash memory with and without JLINK
- Note: using lpc2103MM.ddf & iolpc2103.preliminary.h - these files adapted from other LPC21xx files
  by Mark Moran. Modifications made to date:
  - implemented support for timer 2 and timer 3
  - To be done: implement support for ADC, Fast I/O, change PWM sfrs

Copyright: IAR Systems Software Inc. 2005
Disclaimer: This code is furnished "as is" solely for the purpose of
illustrating how to use the IAR Embedded Workbench integrated development
environment to create code for Philips LPC2xxx ARM7 microcontrollers, and to
illustrate the use of peripherals of that part. Every effort has been made to
ensure that this example works according to the above specifications. Code in
this example may be used freely for any purpose with the understanding that
IAR Systems Software assumes no further responsibility for accuracy or
reliability once it has been partly or fully copied into another application.
By using any portion of this code in other applications,the user takes full
responsibility for code at that time.