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汇编B指令

bad
Intellectual 996 points


  EALLOW
  MOVW  DP,#_EPwm1Regs.TBSTS
  MOV  AL,@_EPwm1Regs.TBSTS
  ANDB  AL,#0x1     ; Check TBCNT1 Direction
  B  Dwn_Cnt,EQ    ; If equal to 0 (Counting Down)  注释是不是写错了？

EQ = 1，而NEQ = 0

  • 0
    Intellectual 996 points

    求帮忙确认一下

  • 0
    Intellectual 996 points

     是不是要改一下：B  Dwn_Cnt, NEQ    ; If equal to 0，计数器减模式

  • 0
    TI__Mastermind 23997 points

    SPRU430F应用文档第161页开始，EQ是指Zflag =1，NEQ是指Zflag =0, 

    After the shift, the Z flag is set if the ACC value is zero, else Z is cleared. Even if the T register specifies a shift of 0, the content of the ACC register is still tested for the zero condition and Z is affected.

    Z位的定义，B指令的含义：

    Conditional branch. If the specified condition is true, then branch by adding the signed
    16-bit constant value to the current PC value; otherwise continue execution without
    branching:
    If (COND = true) PC = PC + signed 16-bit offset;
    If (COND = false) PC = PC + 2;

    所以如果此时ACC = 0，那就跳转Dwn_Cnt，如果不等于0，就继续往下走

  • 0 回复 囧
    Intellectual 996 points

    这个跟ACC没有关系吧，EQ是指Zflag =1，

    B Dwn_Cnt,EQ 这句话不是应该这样解释：如果相等就跳转到Dwn_Cnt，否则继续往下走？

  • 0 回复 bad
    TI__Mastermind 23997 points

    仔细看刚刚贴出来的这句话：

    After the shift, the Z flag is set if the ACC value is zero, else Z is cleared. Even if the T register specifies a shift of 0, the content of the ACC register is still tested for the zero condition and Z is affected.

    是如果ACC =0 就跳转