peripheral mode configuration register
| BOOSTEN | BOOSTEN |
| ANASWVDD | GPIO analog switch control voltage selection |
| I2C_PB6_FMP | FM+ drive capability on PB6 |
| I2C_PB7_FMP | FM+ drive capability on PB6 |
| I2C_PB8_FMP | FM+ drive capability on PB6 |
| I2C_PB9_FMP | FM+ drive capability on PB6 |
| I2C1_FMP | I2C1 FM+ drive capability enable |
| I2C2_FMP | I2C1 FM+ drive capability enable |
| I2C3_FMP | I2C1 FM+ drive capability enable |
| I2C4_FMP | I2C1 FM+ drive capability enable |
| FPU_IE | FPU Interrupts Enable |