SNES EPROM Addresses

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Jetpack
Posts: 2
Joined: Mon Jul 22, 2013 2:21 pm

SNES EPROM Addresses

Post by Jetpack »

Many EPROM, like the 27C801, have less address lines than the SNES hi/lo roms have. The highest address line I have seen was an A21 on some TSOP 40's. Are A22 and A23 not used very often, or is there some form of bypass around these addresses?
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qwertymodo
Posts: 775
Joined: Mon Jul 02, 2012 7:46 am

Re: SNES EPROM Addresses

Post by qwertymodo »

More address lines just means it's a bigger ROM. A 32Mbit ROM will have address lines 0-22, 16Mbit 0-21, 8Mbit 0-20, etc. Each additional address line doubles the size.
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Jetpack
Posts: 2
Joined: Mon Jul 22, 2013 2:21 pm

Re: SNES EPROM Addresses

Post by Jetpack »

Great, thanks.
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clocktower
Posts: 2
Joined: Tue Jul 23, 2013 4:31 pm

Re: SNES EPROM Addresses

Post by clocktower »

i have been looking at this 32 mbit 40 pin tsop, and it only has address lines up to 21 not 22. is this normal?

http://www.buyicnow.com/files/datasheet/EEPROM/1070.pdf
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clocktower
Posts: 2
Joined: Tue Jul 23, 2013 4:31 pm

Re: SNES EPROM Addresses

Post by clocktower »

also, the 27c801 has 19 addresses not 20, so does it go 32 mbit 0-21, 16 mbit 0-20, 8 mbit 0-19?
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