用DS18B20来显示当前的温度，低字节存在r7中，高字节存在r6中，在KEILＣ中通过编译测试成功，用的是汇编语言-Using DS18B20 to display the current temperature, low-byte r7 existence, the existence of the high-byte r6, in KEILC tested successfully by the compiler, using assembly language