
Package	QFP180
Manufacturer
First use	1999 ?
Used on	CHAFIO...

"CMC50"

Late SNK custom chip used for protection, bankswitching and latching on CHAFIO CHA boards.

Descrambling/decryption infos can be found in [MAME:prot_cmc.c]

Versions

This chip is a TC190G series Toshiba ASIC developed between 1990 and 1994. Two versions of the chip are known to exist:

TC190G06CF7042
TC190G06CF7050

They contain the logic for:

NEO-ZMC2
NEO-273
New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data in real time (042 version).
New scrambling system that interlaces M1 + (C* + S1) to decrypt all the graphics ROMs data and Sound Driver ROM data in real time (050 version).

The first released NEO-MVS CHAFIO PCBs came out with the 042 version of NEO-CMC, on the following cartridges:

On this version only the S1 and C ROMs are encrypted and M1 remains unencrypted. Almost one year later, SNK decided to add one more layer, this time also encrypting M1. This new NEO-CMC chip had the 050 reference and was found in the following cartridges:

Until today, nobody has released a cloned chip on the underground market.

Fix handling

See fix bankswitching.

Encryption

Todo.

Pinout

OpenOffice Draw file: File:Neocmc 7050 7042.odg

Signals:

CXe_D[0..15]: C odd data bus
CXo_D[0..15]: C even data bus
CX_A[0..21]: C1~8 address bus (NEO-MVS & NEO-AEG)
CX_A[0..22]: C1~4 address bus (NEO-MVH only)

Pin : 32 connects to Mitsumi (PST600D) reset generator to re-initialize the NEO-CMC in case of power failure.
Pins: 87 and 88 contains a RC circuit clock driver like in a 8085 with X1 and X2 pinouts
Pins: 89 and 92 are interconnected.
-----------------------------------------------
Pins: 62~69, 71~78, 80~84 are configured in:
     NEO-MVS CHAFIO as CR31~CR24, CR23~CR16, CR15~CR11 respectively
     NEO-AEG CHAFIO as   NC~NC  ,   NC~NC  ,   NC~NC
-----------------------------------------------
Pins: 102, 103~106, 107~110, 112~113 are configured in:
     NEO-MVS CHAFIO as CR10, CR9~CR6 ,  CR5~CR2 ,  CR1~CR0
     NEO-AEG CHAFIO as NC  ,GBD3~GBD0, GAD3~GAD0, DOTB~DOTA
-----------------------------------------------
Pin : 94 is configured in:
     NEO-MVS CHAFIO as NC 
     NEO-AEG CHAFIO as 12M
-----------------------------------------------
Pin :147 is configured in:
     NEO-MVS CHAFIO (2003.07.24) as M1_CE
     NEO-MVS CHAFIO (1999.06.14) as NC
     NEO-AEG CHAFIO (2003.07.24) as M1_CE
     NEO-AEG CHAFIO (1999.08.10) as NC

Comparing MVH PCBs vs MVS & AES Cartridges

Pin :147 is configured in:
     NEO-MVH MVOC   (2003.11.03) as M1_CE (KOF2003 pcb)
     NEO-MVH MVOBR  (2003.08.04) as M1_CE (MSLUG5 pcb)
     NEO-MVH MVOB   (2003.07.09) as NC    (SVC pcb) - M1_CE (fixed by wirewrapps)
     NEO-MVH MVO    (2003.06.05) as NC    (SVC pcb) 
     NEO-MVS CHAFIO (2003.07.24) as M1_CE
     NEO-MVS CHAFIO (1999.06.14) as NC
     NEO-AEG CHAFIO (2003.07.24) as M1_CE
     NEO-AEG CHAFIO (1999.08.10) as NC
-----------------------------------------------
Pin :152 is configured in:
     NEO-MVH (MVOC) as VCC
     NEO-MVH (MVO, MVOB, MVOBR) as GND
     NEO-MVS (ALL) as GND
     NEO-AEG (ALL) as GND
-----------------------------------------------
Pin :153 is configured in:
     NEO-MVH (ALL) as VCC
     NEO-MVS (ALL) as VCC
     NEO-AEG (ALL) as GND
-----------------------------------------------
Pin :154 is configured in:
     NEO-MVH (MVO, MVOB, MVOBR, MVOC) as C2C1_OE
     NEO-MVS (ALL) as NC
     NEO-AEG (ALL) as NC
-----------------------------------------------
Pin :155 is configured in:
     NEO-MVH (MVO, MVOB, MVOBR, MVOC) as C4C3_OE
     NEO-MVS (ALL) as NC
     NEO-AEG (ALL) as NC
-----------------------------------------------
Pin :158 is configured in:
     NEO-MVH (MVO, MVOB, MVOBR, MVOC) as NC
     NEO-MVS (ALL) as C8C7_OE
     NEO-AEG (ALL) as C8C7_OE
-----------------------------------------------
Pin :159 is configured in:
     NEO-MVH (MVO, MVOB, MVOBR) as NC
     NEO-MVH (MVOC) as C6C5_OE
     NEO-MVS (ALL) as C6C5_OE
     NEO-AEG (ALL) as C6C5_OE
-----------------------------------------------
Pin :160 is configured in:
     NEO-MVH (MVO, MVOB, MVOBR) as NC
     NEO-MVH (MVOC) as C4C3_OE
     NEO-MVS (ALL) as C4C3_OE
     NEO-AEG (ALL) as C4C3_OE
-----------------------------------------------
Pin :161 is configured in:
     NEO-MVH (MVO, MVOB, MVOBR) as NC
     NEO-MVH (MVOC) as C2C1_OE
     NEO-MVS (ALL) as C2C1_OE
     NEO-AEG (ALL) as C2C1_OE
-----------------------------------------------
Pin :189 is configured in:
     NEO-MVH (MVO, MVOB, MVOBR, MVOC) as A22 (128Mbit) (connected from CMC to the driver input and from output to C ROM's A22)
     NEO-MVS (ALL) as NC
     NEO-AEG (ALL) as NC
-----------------------------------------------
Pin :190 is connected from CMC to the driver input, but NC from it's output:
     NEO-MVH (MVO, MVOB, MVOBR, MVOC) as A23 (256Mbit) (assumption it's prepared for big size C ROMs )
     NEO-MVS (ALL) as NC
     NEO-AEG (ALL) as NC
-----------------------------------------------
Pin :191 is connected from CMC to the driver input, but NC from it's output:
     NEO-MVH (MVO, MVOB, MVOBR, MVOC) as A24 (512Mbit) (assumption it's prepared for big size C ROMs)
     NEO-MVS (ALL) as NC
     NEO-AEG (ALL) as NC

Final Notes

NOTE1: There are no pinout differences between NEO-CMC42 and NEO-CMC50 however, differences can be spotted between previous and later board releases with respect to some setup lines and pin 147. A substantial setup difference can be found comparing the boards of AES and MVS releases. The way the chip access and delivery the graphic data is different between them and both configurations are available inside the NEO-CMC that is configured by the setup of the board itself. So the NEO-CMC is interchangeable between boards between MVS, AES, and MVH embedded. See the releases at (CHAFIO)

NOTE2: In case somebody wonders, it's impossible to downgrade or upgrade NEO-CMCs between different versions (from 42 to 50 and vice-versa). The reason is that it's impossible without preparing the game for that and the algorithm to do it is unknown.

NOTE3: In MVH with embedded CHAFIO the NEO-CMC50 (pin 147 as M1_CE) is native present on the follow releases: 2003.08.04 (MSLUG 5) and 2003.11.03 (KOF2003). However on releases 2003.06.05 and 2003.07.09, both from SVCChaos (set1 and set2), that pin is natively configured as NC, but artificially fixed on set2 by wirewraps.

NOTE4: In MVH release 2003.11.03 (KOF2003) only, there is one configuration change that not appear in any other board AES, MVS or MVH. The pin 152 is connected to VCC. This require further investigation to check what's being switched. Perhaps from 64mbits to 128Mbits?

NOTE5: In MVH (ALL) the pins 158~161 as the MVS, are connected to NC instead of CXeCXo_OE.
          the pin 154 is connected to C2C1_OE 
          the pin 155 is connected to C4C3_OE.

NOTE6: In MVH (ALL) the pins: 
       189 is connected to through buffer driver to A22 (128Mbit), 
       190 and 191 are pre-connected to the buffer drivers and left as NCs from there. 
       The assumption here is that the CMC is ready for bigger C Roms (256Mbit and 512Mbit). 
       Question: Would be easy left them shorted to VCC or GND. Why make parallel tracks without necessity?).

NEO-CMC

Contents

Versions

Fix handling

Encryption

Pinout

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