You often have to wait for an event, such as wait until the timer overflows, or until someone
pushes a switch. Here is how to wait until a particular bit of a register is set or cleared.

• To wait until a bit is set (e.g., wait until Bit 7 of TFLG2 is set):

  loop:  brclr  TFLG2,#$80,loop           while((TFLG2 & 0x80) == 0) ;
  
                                          while(!(TFLG2 & 0x80)) ;
  

• To wait until a particular bit is clear (e.g., wait until Bit 0 of PORTB is clear):

  loop:  brset  PORTB,#$01,loop           while((PORTB & 0x01) == 0x01) ;
  
                                          while(PORTB & 0x01) ;