Oracle Message ORA-00827 - could not shrink sga_target to specified value

ERRORcould not shrink sga_target to specified value
CAUSEAttempted to shrink the SGA to the specified value but did not succeed because the SGA components could not be shrunk as they were already at their minimum sizes.
ACTIONDo not set sga_target to a value below the current value without first shrinking the individual SGA components.