NEO-MGA: Difference between revisions

From NeoGeo Development Wiki
Jump to navigation Jump to search
mNo edit summary
m (Split CD/MVS pinouts)
(6 intermediate revisions by the same user not shown)
Line 1: Line 1:
[[File:cd1_neo-mga.jpg|right|thumb|NEO-MGA chip found in a CD1 system.]]
{{ChipInfo
|picture=cd1_neo-mga.jpg
|pkg=QFP160
|manu=fujitsu
|date=1994 ?
|gates=?
|used_on={{PCB|CDROM-2 board|CDROM-2}}, {{PCB|MV1A}}...
}}


[[File:cd2_mga.jpg|right|thumb|NEO-MGA-T chip found in a CD2 system.]]
Multi-purpose chip found in CD systems and some late MVS boards:
* NEO-MGA in the CD1 model (front loading).
* {{Chipname|NEO-MGA-T}} in the CD2 model (top loading) and {{PCB|MV1A}} MVS boards. Probably the same but made by Toshiba.
* {{Chipname|NEO-MGA-T2}} in the [[CDZ]], probably the exact same chip made with a different pinout or manufacturing process.


NEO-MGA is a damn custom chip apparently noone knows about, which is found in 3 versions in the CD systems:
It is used for address decoding, communication with the [[CD drive]], for refreshing {{Chipname|68k}} [[DRAM]], and for buffering serial [[CDDA]] data.
*NEO-MGA in the CD1 model (front loading)
*NEO-MGA-T in the CD2 model (top loading)
*NEO-MGA-T2 in the CDZ probably able to handle the faster CD reading speeds and the new [[copy protection]] system.)


It's used for communication between the main board and the [[CD modules|CD module]], for handling [[DRAM]] access (?) and for buffering [[CDDA]] data.
=CD pinout=


=Pinout=
[[File:Neo-mga_CD_pinout.png|700px]]


[[File:Neo-mga.png]]
[[File:Neo-mga_cd.odg]]


=Pinout (NEO-MGA-T)=
=MV1A pinout=


1,10,15,16,18,30,41,50,59,70,81,90,110,121,130,139,150: Ground.
[[File:Neo-mga_MV1A_pinout.png|700px]]
 
[[File:Neo-mga_mv1a.odg]]
 
=Signals=
 
* DRM*, RAS, CAS, WRITE: See TC514400 DRAM datasheet.
* X*: See [[LC8953]] datasheet.


[[Category:Chips]]
[[Category:Chips]]

Revision as of 07:34, 11 May 2018

File:Cd1 neo-mga.jpg
Package QFP160
Manufacturer
First use 1994 ?
Used on CDROM-2 board, MV1A...

Multi-purpose chip found in CD systems and some late MVS boards:

  • NEO-MGA in the CD1 model (front loading).
  • NEO-MGA-T in the CD2 model (top loading) and MV1A MVS boards. Probably the same but made by Toshiba.
  • NEO-MGA-T2 in the CDZ, probably the exact same chip made with a different pinout or manufacturing process.

It is used for address decoding, communication with the CD drive, for refreshing 68k DRAM, and for buffering serial CDDA data.

CD pinout

File:Neo-mga cd.odg

MV1A pinout

File:Neo-mga mv1a.odg

Signals

  • DRM*, RAS, CAS, WRITE: See TC514400 DRAM datasheet.
  • X*: See LC8953 datasheet.