Rol

Syntax

Rol Variable {,Set or Clear}

Overview

Bitwise rotate a variable left with or without the microcontroller’s Carry flag.

Parameters

Variable may be any standard variable type, but not an array. Set or Clear are optional parameters that will clear or set the Carry flag before the rotate. If no parameter is placed after the Variable, the current Carry flag state will be rotated into the LSB (Least Significant Bit) of variable.

Example.

      ' Demonstrate the Rol Command
      '
         Device = 24FJ64GA002
                                            ' Select the device to compile for
         Declare Xtal = 32
         Declare Hserial_Baud = 9600
                                            ' UART1 Baud rate
         Declare Hrsout1_Pin = PORTB.14
                                            ' Select the pin for TX with USART1
         Dim bIndex As Byte
         Dim MyByte As Byte
         Dim Byteout As Byte
         RPOR7 = 3
                                            ' Make Pin RP14 U1TX
      '
      ' Rotate the carry through MyByte
      '
         MyByte = %10000000
         Rol MyByte
         Rol MyByte
         Rol MyByte
         Rol MyByte
         Rol MyByte
         Rol MyByte
         Rol MyByte
         Rol MyByte
      '
      ' Set each bit of MyByte with every rotate
      '
         MyByte = %00000000
         For bIndex = 0 To 7
           Rol MyByte, Set
           HRSOutLn Bin8 MyByte
         Next
         HRSOutLn "----------"
      '
      ' Clear each bit of MyByte with every rotate
      '
         MyByte = %11111111
         For bIndex = 0 To 7
           Rol MyByte, Clear
           HRSOutLn Bin8 MyByte
         Next
         HRSOutLn "----------"
'
' Transfer the value of MyByte to Byteout, but reversed
'
  MyByte = %10000000
  Byteout = %00000000
  For bIndex = 0 To 7
     Rol MyByte
     Ror Byteout
     HRSOutLn Bin8 Byteout
  Next
'
' Configure for internal 8MHz oscillator with PLL
' OSC pins are general purpose I/O
'
  Config Config1 = JTAGEN_OFF, GCP_OFF, GWRP_OFF, BKBUG_OFF,_
                   COE_OFF, ICS_PGx1, FWDTEN_OFF, WINDIS_OFF,_
                   FWPSA_PR128, WDTPOST_PS256
  Config Config2 = IOL1WAY_OFF, COE_OFF, IESO_OFF, FNOSC_FRCPLL,_
                    FCKSM_CSDCMD, OSCIOFNC_ON, POSCMOD_NONE

See also: Ror.