buf

代码说明：

  把一个8位二进制数的各位用ASCII码表示之（亦即为“0”的位用30H表示，为“1”的位用31H表示）。该数存放在内部RAM中byte单元中。变换后得到的8个ASCII码存放在外部RAM以buf始的存储单元中去。(To an 8-bit binary numbers that you use the ASCII code (which is " 0" bit with the 30H, said, " 1" bit said with 31H). The number stored in the internal RAM of byte unit. Transform ASCII code 8 by the external RAM to be stored in buf to the beginning of the storage unit.)