ST ST10F276E - CAN Protocol Related Registers; Hardware Reset Description

CAN modules UM0404
424/564 DocID13284 Rev 2
21.8.1 Hardware reset description
After hardware reset, the registers of the C-CAN hold the values described in Table 60.
Additionally the busoff state is reset and the output CAN_TxD is set to recessive (HIGH).
The value 0x0001 (Init = ‘1’) in the CAN Control Register enables the software initialization.
The C-CAN does not influence the CAN bus until the CPU resets Init to ‘0’.
The data stored in the Message RAM is not affected by a hardware reset. After Power-On,
the contents of the Message RAM is undefined.
21.8.2 CAN protocol related registers
These registers are related to the CAN protocol controller in the CAN Core. They control the
operating modes and the configuration of the CAN bit timing and provide status information.
CAN control register
CAN1CR (EF00h) XBUS Reset Value: 0001h
CAN2CR (EE00h) XBUS Reset Value: 0001h
CAN Base + 0xB0 Message Valid 1 0x0000 read only
CAN Base + 0xB2 Message Valid 2 0x0000 read only
CAN Base + 0xB4 - 0xBE — reserved —
(2)
1. r signifies the actual value of the CAN_RxD pin.
2. Reserved bits are read as ‘0’ except for IFx Mask 2 Register where they are read as ‘1’.
3. The two sets of Message Interface Registers - IF1 and IF2 - have identical functions.
Table 60. C-CAN register memory space summary
Address Name Reset value Note
1514131211109876543210
--------TestCCEDAR-EIESIEIEInit
RW RW RW RW RW RW RW
Bit Function
Init
Initialization
’0’: Normal Operation.
’1’: Initialization is started.
IE
Module Interrupt Enable
’0’: Disabled - Module Interrupt IRQ_B is always HIGH.
’1’: Enabled - Interrupts will set IRQ_B to LOW. IRQ_B remains LOW until all
pending interrupts are processed.
SIE
Status Change Interrupt Enable
’0’: Disabled - No Status Change Interrupt will be generated.
’1’: Enabled - An interrupt will be generated when a message transfer is successfully
completed or a CAN bus error is detected.