在MCS-51指令系统中,十进制数的调整指令仅有一条加法调整指令(DA A)而没有对应的减法调整指令,但在实际工作中,不仅常常遇到十进制数的加法调整,而且也常常遇到十进制数的减法调整,为了方便使用,本文给出一种简便、实用的减法调整方法,使用时就象使用DA A指令一样。框图如图1所示。程序如下: In the MCS-51 instruction system, the decimal instruction only has one DA instruction and no corresponding subtraction instruction. However, in practical work, it is not only commonly encountered that decimal addition and adjustment, but also often Encounter decimal subtraction adjustment, in order to facilitate the use of, this article gives a simple and practical method of subtraction adjustment, the use of the same as the use of DA A instructions. Block diagram shown in Figure 1. The procedure is as follows: