Work RAM: Difference between revisions

Revision as of 08:54, 10 July 2023

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. [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]

References

[1] https://problemkaputt.de/fullsnes.htm#snesmemoryworkramaccess
[2] https://problemkaputt.de/fullsnes.htm#snescontrollersotherinputs
page 1 of Book II, "Super NES Parts List" in the official Nintendo development manual
page 2-22-1 of Book II, lbid
[5] caution #11: page 2-24-3 of Book I

@@ Line 5: / Line 5: @@
 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, it is recommended to check to make sure the contents are correct after a reset.  [5]
+WRAM is left intact by a [[Reset]]. [2]  But, Nintendo still recommendeds checking to make sure the contents are correct after a reset.  [5]
 [[Category:SNES Hardware]]