A little bit overclocking for CASSIOPEIA FIVA MPC-102

There are good informations by other. Fiva Modifications

Generally, there are two ways to perform overclocking.

speed up the base clock.
raise up the PLL multiply factor.

I found the second way (PLL setting).

Where are the CLKMODE signals?

The CLKMODE signals are placed in the red-box in following picture.

I found CLKMODE signals of Geode (MPC-10x's CPU). However, not all were found. See following picture, it is in red box.

The CLKMODE2 was not found although only CLKMODE1 and CLKMODE0 found it.

The following is enlarged.

I seem that upper part is CLKMODE1, lower part is CLKMODE0.

The chip resistors are very small. Be careful, don't miss it.

I think that it is a right way to change the place of resistors. But I remove the chip resistors. I short-circuited the pads by deep black drawing pencil. Because it is easier than replacing.

The relation between CLKMODE setting and PLL multiply factor

There are four pads in the upper red box, and similarly four pads in the lower red box.

These pads are following.


          +------+  +------+  +------+  +------+
CLKMODE1  |pad10 |  |pad11 |  |pad12 |  |pad13 |
          +------+  +------+  +------+  +------+

          +------+  +------+  +------+  +------+
CLKMODE0  |pad00 |  |pad01 |  |pad02 |  |pad03 |
          +------+  +------+  +------+  +------+

To short-circuited left two-pads (padx0-padx1), it means '1'.

To short-circuited right two-pads (padx2-padx3), it means '0'.

It looks like following that the relation between the CLKMODE signals and PLL multiply factor.

CLKMODE1 0 0 1 1

CLKMODE0 0 1 0 1

CPU CORE CLK x4 x6 x7 x8

CLKMODE1	0	0	1	1
CLKMODE0	0	1	0	1
CPU CORE CLK	x4	x6	x7	x8

A booting problem

There is a serious problem. My MPC-102 cannot boot at x8 setting (=266MHz).

It looks effective to change the PLL setting on the fly.

I was able to work my MPC-102 at x8 setting(=266MHz) by the following method. It seems effective to change the PLL setting during operation.

Before booting (before powered-on), select x7 (=233MHz) setting.
After booted, select x8 (=266MHz) setting.

This method isn't my original. It was found by Mr.Teekam. Thanks!

According to my MPC-102, when all the pads are opened, selected x7 (=233MHz) setting.

I attached a switch to CLKMODE0 singal. My MPC-102 CLKMODE signals are showing below.

           short pad10-pad11 by pencil line
          +------+  +------+  +------+  +------+
CLKMODE1  |pad10 +--+pad11 |  |pad12 |  |pad13 |
          +------+  +------+  +------+  +------+

          +------+  +------+  +------+  +------+
CLKMODE0  |pad00 |  |pad01 |  |pad02 |  |pad03 |
          +--+---+  +--+---+  +------+  +------+
             |         |
             R         |
             |         |
             +---SW----+
        If shorted, x8 (266MHz) will be selected.
        If opened, x7 (233MHz, needed at boot time) will be selected.

Observing running at 266MHz

I could not feel the changing PLL effective.

I can observe CPU CORE CLK by "WCPUID". The "WCPUID" is produced by Mr.H.Oda!, following URL.

H.Oda!'s Home Page

I can see working at 266MHz using this tool.

Run "wcpuid"->Tweaks->Real Time Clock Checker.

The only "Real Time Clock Checker" runs, it seems that the other functions don't run on FIVA.

Acknowledgement

Thanks a lot for...

Mr.Teekam, who found that the PLL change on the fly is effective and also found that it can observe CPU CORE CLK frequency by using the tool "WCPUID".

Mr.Bee, who gave me a lot of advice about my BAD English. ...This text is still bad, I'm to blame for it. He isn't to blame, of course.

The useful dictionaries in goo.

The excite translator site.

The anonymous-anywhere-always (ITSUDEMO-DOKODEMO-NANASHISAN @ 2CHANNEL), who gave me an advice checking this text by the site (the excite).

Mr.H.Oda!, who provide the tool "WCPUID".

my homepage

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