timer0_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 1000Hz 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 = 500, set a flag in foreground loop to signal .1 second elapsed
5. clear flag in foreground loop when set
6. Toggle the state of port pin P0.6 to blink LED6 on row of LEDs
7. Configure External Interrupt 1 and 2 to interrupt when buttons on the LPC2103 board pushed
8. 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.
9. Application should run out of flash or RAM
10. 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. Count the number of times buttons connected to EXTINT1 and EXTINT2 are pressed and light
    leds 8 and 10 respectively when these buttons pressed.
13. Handle undefined instruction, instruction prefetch and data abort by C functions that
    spin in a while(1); loop.

Author: Mark Moran

Last Date Modified: 30 Dec 2005
Status:
- Works as specified from RAM with JLINK.
- Temporarily using LPC2148 header and .ddf files

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.