Difference between revisions of "Shift left"

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Used to execute a logical bitwise operation shift left. Use [[shift_right]] to shift right.<br />
 
Used to execute a logical bitwise operation shift left. Use [[shift_right]] to shift right.<br />
 
In the example below we'll use R1 to store a 7Bit value 100 decimal (127 decimal value maximum) and 2 seperate flags set true.<br />
 
In the example below we'll use R1 to store a 7Bit value 100 decimal (127 decimal value maximum) and 2 seperate flags set true.<br />
1100100 = 100 Decimal<br />
+
1100100 = 100 Decimal<br />
1 = Flag 1 true<br />
+
1 = Flag 1 true<br />
1 = Flag 2 true<br />
+
1 = Flag 2 true<br />
Value to store 110010011 (403 decimal, 193 hex)
+
Value to store 110010011 (403 decimal, 193 hex)
  
 
==Example==
 
==Example==

Revision as of 16:25, 4 May 2011

Syntax

Syntax: shift_left register1, register2

  • register1 = Register to shift left
  • register2 = Shift left by value of register2

Use

Used to execute a logical bitwise operation shift left. Use shift_right to shift right.
In the example below we'll use R1 to store a 7Bit value 100 decimal (127 decimal value maximum) and 2 seperate flags set true.

1100100 = 100 Decimal
1 = Flag 1 true
1 = Flag 2 true
Value to store 110010011 (403 decimal, 193 hex)

Example


100:     leti R1, 00000193 //Set R1 to 403 (110010011 in binary)
         let R2, R1 //This will be used for 7bit value
         leti R5, 00000002 //This will be used to store the SHIFT amount
         andi R2, 000001FC //Perform bitwise AND operation on R2 using 111111100 binary. R2 now equals 110010000
         shift_right R2, R5 //Perform bitwise SHIFT RIGHT on R2. Value changed from 400 (110010000) to 100 (1100100)
         let R3, R1 //This will be used to store the first flag
         let R4, R1 //This will be used to store the second flag
         ret 

Also see

List of OP Codes used in example.