Clock: Difference between revisions

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[[File:Clkdistribution.png|frame]]
[[File:Clkdistribution.png|frame]]
[[File:Cd2_quartz.jpg|thumb|System clock and color burst generation circuit on a CDM3-2 board.]]


The main system clock is 24MHz. It is then divided by [[NEO-D0]] to 12MHz for the [[68k]], 6MHz for the [[GPU]] and 1MHz (?).
== In cartridge systems ==
 
The main system clock is 24MHz. It is generated and divided by 2, 4 and 24 by [[NEO-D0]] to form the 12MHz clock for [[NEO-ZMC2]], the inverted 6MHz one for the [[video DAC]] and also the 1MHz one for [[NEO-B1]] (?).


[[LSPC2-A2]] divides the 24MHz clock to 8MHz for the [[YM2610]] and 4MHz for the [[Z80]].
[[LSPC2-A2]] divides the 24MHz clock to 8MHz for the [[YM2610]] and 4MHz for the [[Z80]].


[[NEO-GRC]] does this on the NeoGeo CD ?
The cartridge connector provides access to the 24, 12, 8MHz and 4MHz inverted clock signals.


A second quartz is used on NeoGeo systems for generating the color burst frequency for the [[video encoder]]s.
A second quartz is used on NeoGeo systems for generating the color burst frequency for the [[video encoder]]s.
== Clock distribution on MVS systems ==


[[File:clock.png]]
[[File:clock.png]]
"B" signals are phase-inverted.
"B" signals are phase-inverted.
== In CD systems ==
[[File:Cd2_quartz.jpg|thumb|System clock and color burst generation circuit on a CDM3-2 board.]]
[[NEO-GRC]] ?


[[Category:Base system]]
[[Category:Base system]]

Revision as of 17:42, 20 September 2011

File:Clkdistribution.png

In cartridge systems

The main system clock is 24MHz. It is generated and divided by 2, 4 and 24 by NEO-D0 to form the 12MHz clock for NEO-ZMC2, the inverted 6MHz one for the video DAC and also the 1MHz one for NEO-B1 (?).

LSPC2-A2 divides the 24MHz clock to 8MHz for the YM2610 and 4MHz for the Z80.

The cartridge connector provides access to the 24, 12, 8MHz and 4MHz inverted clock signals.

A second quartz is used on NeoGeo systems for generating the color burst frequency for the video encoders.

"B" signals are phase-inverted.

In CD systems

File:Cd2 quartz.jpg
System clock and color burst generation circuit on a CDM3-2 board.

NEO-GRC ?