Note, however, 
that the PM01 to PM00 bits cannot be rewritten to “01b” (memory expansion mode) or “11b” (microprocessor mode) at the same time the PM07 to PM02 bits are rewritten

这句话是什么意思呢？
改写PM07 to PM02的同时，不能改写PM01 to PM00位？

那我如果要设置
PM01 = 0;
PM00 = 1;

又要设置
PM06 = 1;

该怎么办呢？