Tienes varias opciones para hacerlo:
1.- coloca un cristal de 32MHz y pon el fuse HS
2.- coloca un cristal de 8MHz con PLLx4. El fuse sería HSPLL4
3.- utiliza el oscilador interno a 8MHz, con el fuse INTIO2, y luego en tu programa activa el PLLx4 encendiendo el bit PLLEN. Pego a continuación lo que dice el datasheet respecto a esto:
2.6.4 PLL IN INTOSC MODES
The 4x frequency multiplier can be used with the internal oscillator block to produce faster device clock speeds than are normally possible with an internal oscillator. When enabled, the PLL produces a clock speed of up to 32 MHz. Unlike HSPLL mode, the PLL is controlled through software. The control bit, PLLEN (OSCTUNE<6>), is used to enable or disable its operation.
The PLL is available when the device is configured to use the internal oscillator block as its primary clock source (FOSC3:FOSC0 = 1001 or 1000). Additionally, the PLL will only function when the selected output frequency is either 4 MHz or 8 MHz (OSCCON<6:4> = 111 or 110). If both of these conditions are not met, the PLL is disabled. The PLLEN control bit is only functional in those
internal oscillator modes where the PLL is available. In all other modes, it is forced to ‘0’ and is effectively unavailable.
No sé a qué te refieres con el intercambio de ideas; si estás sugiriendo que puedes aportarlas, publícaras en el foro, que para eso está.
