I would like to ask if the 8255A chip can only select one port at a time. After defining the address for the port, such as Q8255A XBYTE...

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I would like to ask if the 8255A chip can only select one port at a time. After defining the address for the port, such as Q8255A XBYTE... [Copy link]

I would like to ask if the 8255A chip can only select one port at a time. After defining the address for the port, such as Q8255A XBYTE[0x1CFF], if you want to use port A in the program, you can directly enter Q8255A. Also, if you use 8255A to connect the address lines A0 to A7 of the ISD2560 chip, can you assign values to 8255A and then have 8255A give the ISD2560 chip the initial value?

一脸懵逼

I would like to ask if the 8255A chip can only select one port at a time. After defining the address for the port, such as Q8255A XBYTE[0x1CFF], if you want to use port A in the program, you can directly enter Q8255A. Also, if you use 8255A to connect the address lines A0 to A7 of the ISD2560 chip, can you assign values to 8255A and then have 8255A give the ISD2560 chip the initial value?

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Is there anyone who can help me take a look?

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Can anyone help me take a look?

chunyang

Of course, only one port can be operated at a time, and 8255 can of course be used for address extension.

huo_hu

I have never used the chip you mentioned, so I don't know the initial configuration. The 8255 operating software only needs to assign values to the addresses, and there are some logical actions in the hardware.