configuration register 1
| FWDIS | Firewall disable  |  
| BOOSTEN | I/O analog switch voltage booster enable  |  
| I2C_PB6_FMP | Fast-mode Plus (Fm+) driving capability activation on PB6  |  
| I2C_PB7_FMP | Fast-mode Plus (Fm+) driving capability activation on PB7  |  
| I2C_PB8_FMP | Fast-mode Plus (Fm+) driving capability activation on PB8  |  
| I2C_PB9_FMP | Fast-mode Plus (Fm+) driving capability activation on PB9  |  
| I2C1_FMP | I2C1 Fast-mode Plus driving capability activation  |  
| I2C2_FMP | I2C2 Fast-mode Plus driving capability activation  |  
| I2C3_FMP | I2C3 Fast-mode Plus driving capability activation  |  
| FPU_IE | Floating Point Unit interrupts enable bits  |