14.2.3.2 I²C Clock Requirements

The I2C_0 and I2C_1 peripherals are clocked by APB_0_CLK on APB bus 0 and APB_1_CLK on APB bus 1. These clocks are derived from the main MSS clock M3_CLK. Each APB clock can be programmed individually as M3_CLK divided by 1, 2, 4 or 8. For more information, see UG0449: SmartFusion2 and IGLOO2 Clocking Resources User Guide.