Editing Clocks

= Overview =

= A, A+, AB, B, B', C, C', D, D' chassis =
Clock generation is based around one or two "DRCG-lite" (DRCG = Direct Rambus Clock Generator) clockgen ICs by varying manufacturers (Cypress CY2212 or TI CDCR61A).

===DRCG-lite #1===
All of these boards have an DRCG-lite IC which has an 18.432 Mhz XTAL connected to it's inputs. This DRCG-lite is set for a multiplier of 64/3 and thus creates a 393.216 Mhz clock for [[Emotion Engine|EE]] and [[Rambus DRAM|RDRAM]].

===DRCG-lite #2===
''This additional DRCG is not found on boards from the same chassis types that use the second revision GS (CXD2944GB) (GH-004, GH-006, GH-008, GH-010, GH-013).''

All boards that have the original [[Graphics_Synthesizer|GS]] with metal heat spreader, CXD2934GB (GH-001, GH-003, GH-005, GH-007, GH-012, GH-014, GH-016), have a second DRCG-lite IC (also with an 18.432 Mhz XTAL) which is set to a multiplier of 16 to generate a 294.912 Mhz clock which is fed into GS.
= F, G, H chassis =
Based around one "DRCG-lite" and one "GMCG" (=Graphics Media Clock Generator, e.g. Cypress CY24141) clock generator. 

===GMCG===
The GMCG has a 18.432 Mhz XTAL and generates a 54 Mhz or 53.9 Mhz clock for GS (selection between 54 and 53.9 is done via control line from [[SSBUS controller]], later from the SPU2+SSBUS-Controller combo IC) and also creates a 18.432 Mhz input clock for the DRCG-lite. 

===DRCG-lite===
The main clock output of DRCG-lite is set for a multiplier of 64/3 and thus creates a 393.216 Mhz clock for [[Emotion Engine|EE]] and [[Rambus DRAM|RDRAM]]. Additionally, DRCG lite generates a 9.216 Mhz clock signal for GS from the 18.432 Mhz input via a multiplier of 0.5.

= I, J, K, L, M chassis =
Based around one single DRCG-lite compatible clock generator with an 18.432 Mhz XTAL, generating a 393.216 Mhz clock, which additionally also generates the selectable 54 Mhz or 53.9 Mhz clock (e.g. Cypress CY22313).

= N, P, R chassis =
Based around one single clock generator IC with an 18.432 Mhz XTAL, similar, but not identical to the "GMCG" mentioned above. It outputs a 18.432 Mhz clock, a 25 Mhz clock (for the ethernet transceiver) and a (likely switchable) 54/53.9 Mhz clock (for GS, see above). Part number on IC case is always (?) '''627G04LF'''. Not much else is known, since no public datasheet is available.