1.物理类型 可测量的量,用可测量基本单位的整数倍表达。 格式为: physical type definition RANGE range UNITS identifiers 基准单位声名 dentifier abstract literal name END UNITS
1. 物理类型 可测量的量，用可测量基本单位的整数倍表达。 格式为： physical type definition … RANGE range UNITS identifiers; --基准单位声名 identifier = abstract_literal name; END UNITS
Range的结构为: range. attribute name Simple expression tO simple expression Simple expression dOwNTO simple expression 预定义类型:“time
Range的结构为： range … attribute_name 或simple_expression TO simple_expression 或simple_expression DOWNTO simple_expression 预定义类型: “time
B: TYPE measure IS RANGE 0 TO 1,000,000,000 UNITS mm, cm=10 mm; dm= 10 cm m=1000mm; END UNITS
例：TYPE measure IS RANGE 0 TO 1,000,000,000 UNITS mm; cm= 10 mm; dm= 10 cm; m = 1000 mm; END UNITS;
用 measure类型的例子: process size. PROCESS (Sig l) VARIABLE wh: measure BEGIN w:=(100cm+1m)-10mm; h:=20cm+w; sig2 <=z; 其它地方声明。 END PROCESS process size;
用measure类型的例子： process_size: PROCESS (sig1) VARIABLE w,h : measure; BEGIN w: = (100cm + 1 m) - 10 mm; h: = 20 cm + w; sig2 <= z; -- 其它地方声明。 END PROCESS process_size;