DRAMS: Difference between revisions
(pinouts and minimal description of DRAM chips used in ZX Spectrum 16/48) |
(→4532) |
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The A<sub>7</sub> line is omitted for refresh address. | The A<sub>7</sub> line is omitted for refresh address. | ||
===4164=== | |||
64Kx1 bit DRAM chip | |||
16 of this IC make the 128K RAM of the ZX Spectrum48 RAM. | |||
e.g:NEC D4164C-3 | |||
Pinout: | |||
<tt> | |||
{| | |||
| style="text-align:right;" | | |||
NC<br> | |||
D<sub>IN</sub><br> | |||
{{overline|WE}}<br> | |||
{{overline|RAS}}<br> | |||
A<sub>0</sub><br> | |||
A<sub>2</sub><br> | |||
A<sub>1</sub><br> | |||
(+5V) V<sub>CC</sub> | |||
| style="border: 1px solid black" | | |||
1 ° 16<br> | |||
2 15<br> | |||
3 14<br> | |||
4 13<br> | |||
5 12<br> | |||
6 11<br> | |||
7 10<br> | |||
8 9 | |||
|| | |||
GND (0V)<br> | |||
{{overline|CAS}}<br> | |||
D<sub>OUT</sub><br> | |||
A<sub>6</sub><br> | |||
A<sub>3</sub><br> | |||
A<sub>4</sub><br> | |||
A<sub>5</sub><br> | |||
A<sub>7</sub><br> | |||
|} | |||
</tt> |
Revision as of 18:03, 17 October 2016
DRAMS
Dynamic Random Access Memories used in ZX Sopectrum machines.
4116
16Kx1 bit DRAM chip
8 of this IC make the lower 16k part of the ZX Spectrum16/48 RAM.
e.g. NEC D416C-2
Pinout:
(-5V) VEE |
1 ° 16 |
GND (0V) |
4532
32Kx1 bit DRAM chip
The addressing logic uses 8 line (A0 to A7) for row address (RAS) and 7 line (A0 to A6) for column address (CAS). At CAS the A7 line has to be fixed at logic 0 or 1 depending on chip type.
8 of this IC make the upper 32k part of the ZX Spectrum48 RAM.
e.g: TI TMS4532-20NL3 or OKI M3732-L TI TMS4532-20NL4 or OKI M3732-H
Pinout:
NC |
1 ° 16 |
GND (0V) |
A7 should set logical 0 at CAS for TI TMS4532-20NL3 and OKI M3732-L chips, and logical 1 for TI TMS4532-20NL4 and OKI M3732-H chips.
The A7 line is omitted for refresh address.
4164
64Kx1 bit DRAM chip
16 of this IC make the 128K RAM of the ZX Spectrum48 RAM.
e.g:NEC D4164C-3
Pinout:
NC |
1 ° 16 |
GND (0V) |