NEO-MGA: Difference between revisions

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NEO-MGA is found in CD systems and some late MVS boards:
Multi-purpose chip found in CD systems and some late MVS boards:
* NEO-MGA in the CD1 model (front loading).
* 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-T}} in the CD2 model (top loading) and {{PCB|MV1A}} MVS boards, can be swapped with NEO-MGA.
* {{Chipname|NEO-MGA-T2}} in the [[CDZ]], probably with a different pinout and maybe stuff related to the [[copy protection]] system.
* {{Chipname|NEO-MGA2-SA}} in the [[CDZ]], replaces the {{Chipname|LC8953}} ?


It is used for communication with the [[CD drive]], for handling {{Chipname|68k}} program and work [[DRAM]] access, some address decoding and for buffering serial [[CDDA]] data.
It is used for address decoding, communication with the [[CD drive]], for refreshing {{Chipname|68k}} [[DRAM]], and for buffering serial [[CDDA]] data.


=Pinout=
=CD pinout=


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


[[File:Neo-mga.odg]]
[[File:Neo-mga_cd.odg]]
 
=MV1A pinout=
 
[[File:Neo-mga_MV1A_pinout.png|700px]]
 
[[File:Neo-mga_mv1a.odg]]


=Signals=
=Signals=

Revision as of 15:12, 1 August 2022

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, can be swapped with NEO-MGA.
  • NEO-MGA2-SA in the CDZ, replaces the LC8953 ?

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.