Difference between revisions of "V ROM"

From NeoGeo Development Wiki
Jump to: navigation, search
m
 
m (Better...)
 
(9 intermediate revisions by the same user not shown)
Line 1: Line 1:
8 bit ROMs containing [[YM2610|PCM]] audio samples in [[cartridges]].
+
[[File:v_rom.jpg|thumb|right|4MiB V ROM]]
 +
The '''V'''(oice ?) ROMs contain the [[ADPCM]] audio samples in [[cartridges]].
  
In early [[cartridges]], V1 ROMs contain ADPCM-A samples. V2 ROMs contain ADPCM-B samples.
+
In early games, the ADPCM-A and ADPCM-B data was stored in separate V ROMs. Later, the {{Chipname|PCM}} demultiplexer chip was made to allow both types of data to be mixed in the same ROM(s).
  
The [[NEO-PCM]] chip was later used to merge data in one V ROM for both channels.
+
The TC5332204 mask ROMs have a similar pinout to the 27C322 EPROMs. The only difference is that they're set to byte mode only: half of the data output pins are unused. Pin 30 (Q15) is used as the address lowest bit.
 +
 
 +
==Speed==
 +
 
 +
* V A ROMs minimum speed: any will do (>2µs).
 +
* V B ROMs minimum speed: 250ns (see [[YM2610 bus timing]]).
  
 
[[Category:Chips]]
 
[[Category:Chips]]
[[Category:Emulation]]
+
[[Category:Cartridge systems]]

Latest revision as of 03:27, 12 April 2018

4MiB V ROM

The V(oice ?) ROMs contain the ADPCM audio samples in cartridges.

In early games, the ADPCM-A and ADPCM-B data was stored in separate V ROMs. Later, the PCM demultiplexer chip was made to allow both types of data to be mixed in the same ROM(s).

The TC5332204 mask ROMs have a similar pinout to the 27C322 EPROMs. The only difference is that they're set to byte mode only: half of the data output pins are unused. Pin 30 (Q15) is used as the address lowest bit.

Speed

  • V A ROMs minimum speed: any will do (>2µs).
  • V B ROMs minimum speed: 250ns (see YM2610 bus timing).