LAUNCHXL-F280049C: About the SWR bit of CAN_CTL Register in DCAN module

Hi,

    According to the 《TMS320F28004x Real-Time Microcontrollers Technical Reference Manual》, the SWR bit of CAN_CTL Register is EALLOW protected. Follow the picture:

My questions are:

1、According to the example "can_ex4_loopback_dma" in C2000Ware_4_01_00_00，in the "CAN_initModule(CANA_BASE)", the SWR bit is not protected by EALLOW."HWREGH(base + CAN_O_CTL) |= CAN_CTL_SWR", Why?

2、But in the F28379,such as "can_ex1_loopback",in the "CAN_initModule(CANA_BASE)", the SWR bit is protected by EALLOW.

"    EALLOW;
    HWREGH(base + CAN_O_CTL) |=  CAN_CTL_SWR;
    EDIS;"  Why?

3、In F280049 and F28379, "This bit is write-protected by Init bit", is it really so?