Talk:6264 static RAM

More pinouts for different sizes of 62* SRAM's

Some extra pinouts for SRAMs: 62256 is identical except for the !CS2 input and NC becoming address lines. This is to make address expansion of a board design almost trivial using inverters as half of an address decoder (other half is !CS input).

CY62256 SRAM (28 pins, 1-14,28-15) Note that the Ax and Dx line order doesn't really matter.
A5 +5V
A6 !WE
A7 A4
A8 A3
A9 A2
A10 A1
A11 !OE
A12 A0
A13 !CS
A14 D7
D0 D6
D1 D5
D2 D4
Gnd D3

62512 SRAM (32 pins, 1-16, 32-17)
A18 +5V
A16 A15
A14 A17
A12 /WE
A7 A13
A6 A8
A5 A9
A4 A11
A3 /OE
A2 A10
A1 /CS
A0 D7
D0 D6
D1 D5
D2 D4
Gnd D3

621024 SRAM (32 pins, 1-16, 32-17)
NC +5V
A16 A15
A14 CS2
A12 /WE
A7 A13
A6 A8
A5 A9
A4 A11
A3 /OE
A2 A10
A1 /CS1
A0 D7
D0 D6
D1 D5
D2 D4
Gnd D3

LY6220488 TSOP-package SRAM (44 pins, 1-22, 23-44)
A4 A5
A3 A6
A2 A7
A1 !OE
A0 CS2
!CS A8
NC NC
NC NC
D0 D7
D1 D6
+5V Gnd
Gnd +5V
D2 D5
D3 D4
NC NC
A20 NC
!WE A9
A19 A10
A18 A11
A17 A12
A16 A13
A15 A14

DS1249Y/AB SRAM (32 pins, 1-16, 32-17) Note that this is equivalent to 622048 but AFAICT, no one makes those.
NC +5V
A16 A15
A14 A17
A12 !WE
A7 A13
A6 A8
A5 A9
A4 A11
A3 !OE
A2 A10
A1 !CS
A0 D7
D0 D6
D1 D5
D2 D4
Gnd D3

DS1250Y/AB SRAM (32 pins, 1-16, 32-17) Note that this is equivalent to 624096 but AFAICT, no one makes those. These are $47 at Maxim's site as of time I last checked! The 1251 is also a 4Mb part, BTW.
A18 +5V
A16 A15
A14 A17
A12 !WE
A7 A13
A6 A8
A5 A9
A4 A11
A3 !OE
A2 A10
A1 !CS
A0 D7
D0 D6
D1 D5
D2 D4
Gnd D3

These would need to be edited to match formatting of the existing Wiki article.

Forgot to sign, and it seems I may have made some mistakes? Pretty sure I got those off of the original datasheets, but maybe a typo snuck in. Can someone please check these? It doesn't make sense that a 512Kb device has more pins than a 1024. I think that's what the article means by "breaking the pattern" since it's apparently 512KB which is 4096 Kb. Maybe I didn't make a mistake at all! Nope, I did. One of my PDFs was mislabeled. UM62512 is definitely only 64KB.

alphamule (talk) 13:42, 28 January 2015 (MST) I found this site which has a nice explanation of the various differences on the bigger chips. http://sblive.narod.ru/ZX-Spectrum/ZX-SEGA/ZX-SEGA.htm Seems also that JEDEC has references. Search for "3_07_05R12.pdf" and you'll find it pn page 3.7.5-11. alphamule (talk) 13:52, 28 January 2015 (MST)