I'm developing a custom CAN bridge with the stm3210c-eval board, such that I can hook up the board's CAN port to a car's CAN bus and the USART port to a computer and read in received frames over a serial terminal. In the CAN interrupt handler I populate a CANRx struct that is shared with my main.c. I want to put in a flag so that the main program knows when to do a printf (which is redirected over USART), which requires that I disable the CAN interrupt (to do a flag check and printf). However, I can't find any exposed interface to block an irq. Does it exist, and if so, what do I need to import?