Use of STM32-CAN bus filter

The shielding filter function of stm32 has requirements for ID. In STM32, ID must be shifted.
Compare the following table:
We set all to 1 here, that is, only accept the data of the node set in CAN_Filter
. STM32 has a total of 14 groups of filters to filter the received frames. Each group of filters includes 2 configurable 32-bit registers: CAN_FxR0 and CAN_FxR1. For the filter group, it can be configured as a shielding bit mode, so that CAN_FxR0 stores the identifier matching value, and CAN_FxR1 stores the shielding code, that is, if a bit in CAN_FxR1 is 1, the corresponding bit in CAN_FxR0 must match the corresponding bit in the identifier of the received frame to pass the filter; the bit in CAN_FxR1 is 0, which means that the corresponding bit in CAN_FxR0 does not need to match the received frame. The filter group can also be configured in the identifier list mode, in which case both CAN_FxR0 and CAN_FxR1 are the identifiers to be matched, and the identifier of the received frame must match one of them to pass the filter.
        Note: CAN_FilterIdHigh refers to the high 16 bits, and CAN_FilterIdLow is the low 16 bits. The frame to be obtained should be aligned with the filter setting value.
        For example:
        
CAN_FilterInitStructure.CAN_FilterNumber=0;                                                                             //First set of filters
CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask;                                        //Mask bit mode
CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit;                                           //32-bit
CAN_FilterInitStructure.CAN_FilterIdHigh=(0x0635<<5);                                                           //Receive message with ID 635, 11-bit frame ID, standard frame is therefore shifted left by 5
CAN_FilterInitStructure.CAN_FilterIdLow=0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0xffff;                                                                //
CAN_FilterInitStructure.CAN_FilterMaskIdLow=0xffff;
CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_FIFO0;                                         //First set of filters points to FIFO0
CAN_FilterInitStructure.CAN_FilterActivation=ENABLE;
CAN_FilterInit(&CAN_FilterInitStructure);
CAN_FilterInitStructure.CAN_FilterNumber=1;                                                                           //The second set of filters
CAN_FilterInitStructure.CAN_FilterIdHigh=(0x06DB<<5);                                                       //Receive messages with ID bit 6db
CAN_FilterInitStructure.CAN_FilterIdLow=0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0xffff;
CAN_FilterInitStructure.CAN_FilterMaskIdLow=0xffff;
CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_FIFO1;                                     //The second set of filters points to FIFO1
CAN_FilterInit(&CAN_FilterInitStructure);
CAN_ITConfig(CAN_IT_FMP0,ENABLE);
CAN_ITConfig(CAN_IT_FMP1,ENABLE);