Playstation Controller Question?

My question is the following: Does any one in here know the clock frequency that the playstation 2 uses with the Playstation Console? I am aware that the clock frequency of the playstation console is 300MHz but i need the information for the controller about its clock frequency.

Thank you.......,

I got my PS1 controller to accept clocking as high as 500kHz before I stopped testing. I'm not certain about PS2 because that model is not well-documented.

Processor: 128-bit "Emotion Engine"
Processor clock speed: 300 MHz
Floating point unit (FPU) co-processor operating at 6.2 gigaflops
Bus speed: 3.2 GB per second
Original Play Station CPU core as I/O processor

Graphics: "Graphics Synthesizer"
150 MHz
Embedded cache
4 MB VRAM
Resolution: 640x480 or 320x240 interlaced
Colors: 24-bit (16,777,216) maximum, as well as 16-bit (65,536) mode
Geometry engine:
Alpha channel
Anti-aliasing
Bezier surfacing
Gouraud shading
Mip mapping
Perspective correction
Z-buffer
Polygon rendering: 75 million polygons per second

Audio: SPU2 (+CPU)
Channels: 48
Sample rate: 44.1 KHz or 48 KHz
Memory: 2 MB RAM
Optical digital output

Memory: 32 MB RDRAM

Operating system: Proprietary Sony

Game medium: Proprietary 4.7-GB DVD
Supports original PlayStation CDs
Video DVD support
Audio CD support

Drive bay (for hard disk or network inteface)

Other features:
Two memory card slots
Two USB ports
FireWire port (called iLink by Sony)