dsp281x_usdelay.lst

基于双向DC-DC变换器

TMS320C2000 COFF Assembler PC Version 3.09 Mon Apr 14 07:41:46 2008

Tools Copyright (c) 1996-2002 Texas Instruments Incorporated
DSP281x_usDelay.asm                                                  PAGE    1

       1              ;//###########################################################################
       2              ;// FILE:  DSP281x_usDelay.asm
       3              ;// TITLE: Simple delay function
       4              ;// DESCRIPTION:
       5              ;// This is a simple delay function that can be used to insert a specified
       6              ;// delay into code.  
       7              ;// This function is only accurate if executed from internal zero-waitstate
       8              ;// SARAM. If it is executed from waitstate memory then the delay will be
       9              ;// longer then specified. 
      10              ;// To use this function:
      11              ;//  1 - update the CPU clock speed in the DSP281x_Examples.h
      12              ;//    file. For example:
      13              ;//    #define CPU_CLOCK_SPEED 6.6667L // for a 150MHz CPU clock speed
      14              ;//  2 - Call this function by using the DELAY_US(A) macro
      15              ;//    that is defined in the DSP28_Device.h file.  This macro
      16              ;//    will convert the number of microseconds specified
      17              ;//    into a loop count for use with this function.  
      18              ;//    This count will be based on the CPU frequency you specify.
      19              ;//  3 - For the most accurate delay 
      20              ;//    - Execute this function in 0 waitstate RAM.  
      21              ;//    - Disable interrupts before calling the function
      22              ;//      If you do not disable interrupts, then think of
      23              ;//      this as an "at least" delay function as the actual
      24              ;//      delay may be longer. 
      25              ;//  The C assembly call from the DELAY_US(time) macro will
      26              ;//  look as follows: 
      27              ;//  extern void Delay(long LoopCount);                
      28              ;//        MOV   AL,#LowLoopCount
      29              ;//        MOV   AH,#HighLoopCount
      30              ;//        LCR   _Delay
      31              ;//  Or as follows (if count is less then 16-bits):
      32              ;//
      33              ;//        MOV   ACC,#LoopCount
      34              ;//        LCR   _Delay
      35              ;//###########################################################################
      36              ;//
      37              ;//  Ver | dd mmm yyyy | Who  | Description of changes
      38              ;// =====|=============|======|===============================================
      39              ;//  1.00| 11 Sep 2003 | L.H. | No changes since v.58
      40              ;//###########################################################################  
      41                     .def _DSP28x_usDelay
      42 00000000              .sect "ramfuncs"
      43                     .global  __DSP28x_usDelay
      44 00000000       _DSP28x_usDelay:
      45 00000000 1901          SUB    ACC,#1
      46 00000001 56C3          BF     _DSP28x_usDelay,GEQ    ;; Loop if ACC >= 0
         00000002 FFFF 
      47 00000003 0006          LRETR 
      48              ;There is a 9/10 cycle overhead and each loop
      49              ;takes five cycles. The LoopCount is given by
      50              ;the following formula:
      51              ;  DELAY_CPU_CYCLES = 9 + 5*LoopCount
      52              ; LoopCount = (DELAY_CPU_CYCLES - 9) / 5
      53              ; The macro DELAY_US(A) performs this calculation for you
      54              ;==================================================
TMS320C2000 COFF Assembler PC Version 3.09 Mon Apr 14 07:41:46 2008

Tools Copyright (c) 1996-2002 Texas Instruments Incorporated
DSP281x_usDelay.asm                                                  PAGE    2


No Assembly Errors, No Assembly Warnings