STM32F103VE Is possible to REMAP PD0 PD1 to connect Xtal ?

[rnavoni9]

Posted on February 22, 2011 at 22:52

STM32F103VE Is possible to REMAP PD0 PD1 to connect Xtal ?

[rnavoni9]

Posted on May 17, 2011 at 14:25

[Tesla DeLorean]

Posted on May 17, 2011 at 14:25

You're not going to be able to remap the pins OSC_IN/OSC_OUT, they are designed to drive the crystal. On the 64-pin package you can connect PD0/PD1 to pins 5/6 after boot instead of the internal oscillator circuit.

Take off the crystal, and run the device from the HSI clock. If you can get to the OSC_IN pin, you could feed it from an external oscillator.

[rnavoni9]

Posted on May 17, 2011 at 14:25

[Tesla DeLorean]

Posted on May 17, 2011 at 14:25

The half speed is because the PLL can only be driven by HSI/2 (the external can be HSE/1 or HSE/2), so the documented max is 64 MHz when you use the 16x multiplier in the PLL.

You probably still have the PLL programmed with the 9x multiplier.

[rnavoni9]

Posted on May 17, 2011 at 14:25

[Tesla DeLorean]

Posted on May 17, 2011 at 14:25

thank you very much for you support i use PLLX 16x and obtain a maximum speed with internal oscillator of 64 mhz .. but is possilbe to overclock the cpu ? What can happen ?

No PLL setting is define above 16x, and the bit pattern 0x3C0000 might as easily indicate 1x, 17x or not work at all. Since it is rated to 72 MHz, speed isn't the limiting fact. If you were running it from an external source you could likely get the PLL to run above 72 MHz, but your biggest problem there would be the wait states on the flash, and it actually performing more slowly.