no speedstep, undervolting, Celeron M

[bulk88]

I have a Celeron M laptop (yonah) that I would like to undervolt. It doesn't have speedstep so most CPU speed changing tools are useless. But still, the CPU only requests a voltage from the mobo, it doesn't make it itself (imagine if a CPU has FETs in the die, end of all volt modding). I just reassembled this laptop, and I really don't want to take it apart to look for the VRM chip and find its datasheet. Are there any tools to directly talk to the VRM chip bypassing Speedstep, like a VRM chip version of CPUFSB?