康芯科技 MHEN13=>z2<=11 当se为1或3时选中 ⅦHEN4To72=>z3<=11"; 当se为2、4、5、6或T时选中 WHEN OTHERS =>z4<=1i 当se为8~15中任一值时选中 END CASE END PROCESS END activ 【例92】 SIGNAL value INTEGER RANGE 0 TO 15 SIGNAL out1: STD LOGIC CASE value IS 缺少以EN引导的条件句 END CASE CASE value Is When O ou七1<=11 --va1ue2~15的值未包括进去 WheN 1=> out1<=I0 END CASE CASE value Is WHEN0To10=。ut1<=11!; 选择值中5~10的值有重叠 WHEN 5 To 15 = outl<=0i END CASE;KX 康芯科技 WHEN 13 => z2<='1' ; -- 当sel为1或3时选中 WHEN 4 To 72 => z3<='1'; -- 当sel为2、4、5、6或7时选中 WHEN OTHERS => z4<='1' ; -- 当sel为8～15中任一值时选中 END CASE ； END PROCESS ； END activ ； 【例9-2】 SIGNAL value : INTEGER RANGE 0 TO 15; SIGNAL out1 : STD_LOGIC ; ... CASE value IS -- 缺少以WHEN引导的条件句 END CASE； ... CASE value IS WHEN 0 => out1<= '1' ; -- value2～15的值未包括进去 WHEN 1 => out1<= '0' ; END CASE ... CASE value IS WHEN 0 TO 10 => out1<= '1'; -- 选择值中5～10的值有重叠 WHEN 5 TO 15 => out1<= '0'; END CASE;