Motorola MCF5282, MCF5281 user manual Programmer’s Model, Can Module Configuration Register Canmcr

Models: MCF5282 MCF5281

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Programmer’s Model

interrupt routine can be fixed at compilation time. Each of the buffers is assigned a bit in the IFLAG register. The bit is set when the corresponding buffer completes a successful transmission or reception, and cleared when the CPU reads the interrupt flag register (IFLAG) while the associated bit is set, and then writes it back as ‘1’ (and no new event of the same type occurs between the read and the write actions).

The other 3 interrupt sources (Bus-off, Error and Wake-up) act in the same way, and are located in the Error & Status register. The Bus-off and Error interrupt mask bits are located in the CANCTRL0 register, and the Wake-up interrupt mask bit is located in the CANMCR.

25.5 Programmer’s Model

This section describes the registers in the FlexCAN module.

NOTE

The FlexCAN has no hard-wired protection against invalid bit/field programming within its registers. Specifically, no protection is provided if the programming does not meet CAN protocol requirements.

Programming the FlexCAN control registers is typically done during system initialization, prior to the FlexCAN becoming synchronized with the CAN bus. The configuration registers can be changed after synchronization by halting the FlexCAN module. This is done when the user sets the HALT bit in the FlexCAN module configuration register (CANMCR). The FlexCAN responds by setting the CANMCR[NOTRDY] bit. Additionally, the control registers can be modified while the MCU is in background debug mode.

25.5.1 CAN Module Configuration Register (CANMCR)

15

14

13

12

11

10

9

8

Field

STOP

FRZ

HALT

 

NOTRDY

WAKEMSK

SOFTRST

FRZACK

 

 

 

 

 

 

 

 

 

Reset

 

 

 

0101_1001

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

R/W

 

 

 

 

 

 

 

 

 

 

 

 

 

7

6

5

4

3

 

 

0

Field

Reset

R/W Address

SUPV

SELFWAKE

APS

STOPACK

 

 

 

 

 

1000_0000

R/W

IPSBAR + 0x1C_0000

Figure 25-6. CAN Module Configuration Register (CANMCR)

Table 25-8describes the CANMCR fields.

25-20

MCF5282 User’s Manual

MOTOROLA

Page 546
Image 546
Motorola MCF5282, MCF5281 Programmer’s Model, Can Module Configuration Register Canmcr, 8describes the Canmcr fields