33.6.2.4.1.2 Host Clock Generation (High-Speed Mode)

For I²C Hs transfers, there is no SCL synchronization. Instead, the SCL frequency is determined by the GCLK_SERCOMx_CORE frequency (f_GCLK) and the High-Speed Baud setting in the Baud register (BAUD.HSBAUD). When BAUD.HSBAUDLOW=0, the HSBAUD value will determine both SCL high and SCL low. In this case the following formula determines the SCL frequency.

$f_{\mathrm{SCL}}=\frac{f_{\mathrm{GCLK}}}{{2+2\cdot HSBAUD}_{}}$

When HSBAUDLOW is non-zero, the following formula determines the SCL frequency.

$f_{\mathrm{SCL}}=\frac{f_{\mathrm{GCLK}}}{{2+HSBAUD+HSBAUDLOW}_{}}$