Figure 335. Dual Can Block Diagram; Bxcan Operating Modes - STMicroelectronics STM32F405 Reference Manual

RM0090
32.4

bxCAN operating modes

bxCAN has three main operating modes: initialization, normal and Sleep. After a
hardware reset, bxCAN is in Sleep mode to reduce power consumption and an internal pull-
up is active on CANTX. The software requests bxCAN to enter initialization or Sleep mode
by setting the INRQ or SLEEP bits in the CAN_MCR register. Once the mode has been
entered, bxCAN confirms it by setting the INAK or SLAK bits in the CAN_MSR register and
the internal pull-up is disabled. When neither INAK nor SLAK are set, bxCAN is in normal

Figure 335. Dual CAN block diagram

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Controller area network (bxCAN)
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