M27C322 in 8Bit mode

[Farid]

M27C322 has A0 ~ A20 and D0 ~ D15 so it is 2MB x 16bit
But I want to use it in 8bit mode (2MB x 8bit), so I just ignore D8 ~ D15 pins completely
For now I am programming it with a custom adapter :



And I select 27C080 in the software
27C080 has A0 ~ A19 and D0 ~ D7 and it is 1MB x 8bit
27C080 doesn't have any A20, so I have to control it manually
So I program the chip two times, first time I connect A20 to GND and second time to 5v
And it works fine

Now my question :
Is there any way to control A20 automatically and program the chip only one time?
In other word I need to select an EPROM in the software which has A0 ~ A20 and D0 ~ D7, is there such a chip?
Thanks in advance

[Ezo]

Mentioned chip organized 16bit only, no 8bit option

[Farid]

First of all thanks for the answer
But it seems you didn't get the point, I am using this chip in 8bit mode and it works fine.
If you don't use D8 ~ D15 data lines, the chip will be 8bit.
And yeah I know by doing so the half of the chip goes waste, but it is ok with me!

I am trying to find a better and faster way to program the chip for 8bit usage.
The obvious method is to select M27C322 in the software and tie the zif socket and J4 pins to the chip (pin to pin) and program a 4MB bin file (2MB Data + 2MB of 00) but this method will take too long to program, and I think it will take double amount of time as the following method.

What do you think about this method :
To program a 2MB data bin file to M27C322, I want to select M27C160 in the software and use this wiring :



I am not just sure about VPP line of zif socket which will be floating, is this ok?
Also when I program the chip I tie D8 ~ D15 to GND, do I have to tie them to GND when I use it (Read mode) or just leave them floating?

Thanks in advance

[Farid]

It seems VPP line of 27C160 isn't compatible with 27C322.
But VPP line of 27C801 is compatible with 27C322 :



So I think wiring is not enough and I have to adjust the DIP switch too :

27C322 :


27C160 :


27C801 :


But how exactly should I adjust the DIP switch?

[Ezo]

look on zif32 and dipswitch extended schematic

[Farid]

Thanks for the schematic, it is very helpful
So I think I have to select 27C160 in the software, but I have to set the DIP switch according to 27C801
The wiring can also be improved as well, by applying a jumper to Pin2 and Pin3 of J4, pin 1 of zif will be A19 (instead of VPP), and I need only one wire to get A20 from J4
Please confirm these setting, as I don't want to fry anything!

[Ezo]

I suppose to use 27C322 for programming as original 16bit chip device where source file modified 32 Mb with low byte as target, high byte n/a or any.You can't use reduced file size in sw.