只不过它们的状态正好相反,当读时,一个为高,一个为低<br /><br />PIN92(R/W):<br />Read/write qualifier signal. R/W indicates transfer<br />direction during communication to an external<br />device. It is normally in read mode (high), unless<br />low level is asserted for performing a write<br />operation. R/W is placed in the high-impedance<br />state.<br /><br />PIN19(W/R):<br />Write/Read qualifier or GPIO. This is an inverted<br />R/W signal useful for zero-wait-state memory<br />normally low, unless a memory write<br />interface. It is operation is performed. See Table 12, <br />Port C section, for reset note regarding LF2406A and<br />LF2402A. (↑) |
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