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Work RAM: Difference between revisions
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[[File:wram schematic.png|thumb|The WRAM chip is straddling regions C1 and D1 in the [[jwdonal schematic]]]] | [[File:wram schematic.png|thumb|The WRAM chip is straddling regions C1 and D1 in the [[jwdonal schematic]]]] | ||
'''WRAM''' (Work RAM) serves as the SNES' main memory. It is 128K x 8 bits (131,072 bytes) in size. It has part number 21326. <sup>[3]</sup> | '''WRAM''' (Work RAM) serves as the SNES' main memory. It is 128K x 8 bits (131,072 bytes) in size, which is exactly two [[banks]]. It has part number 21326. <sup>[3]</sup> | ||
Even though WRAM has both [[Address Bus A]] and [[Address Bus B]] connected to it, the chip can only pay attention to one at a time, so WRAM-to-WRAM [[DMA]] isn't possible. | Even though WRAM has both [[Address Bus A]] and [[Address Bus B]] connected to it, the chip can only pay attention to one at a time, so WRAM-to-WRAM [[DMA]] isn't possible. | ||
WRAM is left intact by a [[Reset]]. <sup>[2]</sup> But, Nintendo still recommendeds checking to make sure the contents are correct after a reset. <sup>[5]</sup> | WRAM is left intact by a [[Reset]]. <sup>[2]</sup> But, Nintendo still recommendeds checking to make sure the contents are correct after a reset. <sup>[5]</sup> WRAM is DRAM and as such must be refreshed. | ||
[[Category:SNES Hardware]] | [[Category:SNES Hardware]] | ||
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[[Category:ICs with unconnected pins]] | [[Category:ICs with unconnected pins]] | ||
[[Category:Address Spaces]] | [[Category:Address Spaces]] | ||
=== See Also === | |||
* [[ARAM]] | |||
* [[VRAM]] | |||
* [[OAM]] | |||
=== References === | === References === | ||
# https://problemkaputt.de/fullsnes.htm#snesmemoryworkramaccess | # https://problemkaputt.de/fullsnes.htm#snesmemoryworkramaccess | ||
# https://problemkaputt.de/fullsnes.htm#snescontrollersotherinputs | # https://problemkaputt.de/fullsnes.htm#snescontrollersotherinputs | ||
# page 1 of Book II, "Super NES Parts List" in the official Nintendo development manual | # [https://archive.org/details/SNESDevManual/book2/page/n404 page 1 of Book II], "Super NES Parts List" in the official Nintendo development manual | ||
# [https://archive.org/details/SNESDevManual/book1/page/n97 page 2-22-1 of Book | # paragraph 22.3 on [https://archive.org/details/SNESDevManual/book1/page/n97 page 2-22-1 of Book I], lbid | ||
# caution #11: [https://archive.org/details/SNESDevManual/book1/page/n105 page 2-24-3 of Book I] | # caution #11: [https://archive.org/details/SNESDevManual/book1/page/n105 page 2-24-3 of Book I] | ||
Latest revision as of 01:55, 12 August 2024
The WRAM chip is straddling regions C1 and D1 in the jwdonal schematic
WRAM (Work RAM) serves as the SNES' main memory. It is 128K x 8 bits (131,072 bytes) in size, which is exactly two banks. It has part number 21326. [3]
Even though WRAM has both Address Bus A and Address Bus B connected to it, the chip can only pay attention to one at a time, so WRAM-to-WRAM DMA isn't possible.
WRAM is left intact by a Reset. [2] But, Nintendo still recommendeds checking to make sure the contents are correct after a reset. [5] WRAM is DRAM and as such must be refreshed.
See Also
References
- https://problemkaputt.de/fullsnes.htm#snesmemoryworkramaccess
- https://problemkaputt.de/fullsnes.htm#snescontrollersotherinputs
- page 1 of Book II, "Super NES Parts List" in the official Nintendo development manual
- paragraph 22.3 on page 2-22-1 of Book I, lbid
- caution #11: page 2-24-3 of Book I