How to enter CC1310 LUNCHPADXL bootloader mode

Do you do mass erase to your LAUNCHXL-CC1310 first?

From www.ti.com/.../swra466 :

You can program the device through the ROM bootloader if:
1) There is no valid flash image in the device (for details on the image valid field you can look in the Technical Reference Manual). - This would be the case for new devices coming from TI.
2) If you have programmed the flash, and set CCFG settings such that the ROM bootloader is enabled and can be accessed by asserting an IO during boot.

If neither of these are fulfilled it is not possible to enter the ROM bootloader and thus not possible to do a mass erase either. You can still erase the device through the JTAG interface though, unless you have deliberately disabled this option in CCFG.

Yes, I did forced mass erase my LAUNCHXL-CC1310. I have 3 of them, and i followed the steps ,mentioned in the following link. But at the end, the serial connection failed. Please suggest me the method to overcome the problem. 

sunmaysky.blogspot.com/.../how-to-use-serial-bootloader-mode-to.html

So,
1. The device had been flashed before.
2. How to set the CCFG settings to enable the ROM bootloader?

You can refer to www.ti.com/.../swra466a.pdf to set CCFG.

If you open the CCFG.c file you will see that the following could be useful to alter for debugging:
SET_CCFG_BL_CONFIG_BOOTLOADER_ENABLE: For security reasons this is set to disable the bootloader after you have uploaded an image.

Since you have some issues I would activate the backdoor (SET_CCFG_BL_CONFIG_BL_ENABLE) and set a pin to be used (SET_CCFG_BL_CONFIG_BL_LEVEL, SET_CCFG_BL_CONFIG_BL_PIN_NUMBER)

Have you verified reading back the flash that your mass erase actually was done?

Dear sir, 

Here are settings, that I have used in ccfg.c file available at contiki/cpu/cc26xx-cc13xx/lib/cc26xxware/startup_files

I have Enabled the ROM boot loader, 

I have SET_CCFG_BL_CONFIG_BL_PIN_NUMBER to 0xB for DIO11 as mentioned in Page 12 of Document: SWRA466A. 

I am using SmartRF Flash Programmer 2 to upload the .bin file to the cc1310 launchpad. I have flashed it with cc26xx-web-demo.bin. The green led blinks continuously. When I did the mass erase, the led stops blinking, So I guess the device gets mass erased. Still I am not able to enter the bootloader.  

Dear sir,

I have gone through the document and did the settings, yet I am not able to enter the bootloader.

If you do mass erase first, can you enter boot loader mode and update FW with serial boot loader?

What do you mean by FW?
and NO I am not able to enter the bootloader after the mass erase.

FW=cc26xx-web-demo.bin for example. So, you cannot use serial boot loader to download cc26xx-web-demo.bin to your LAUNCHXL-CC1310 even after you do mass erase to LAUNCHXL-CC1310?

No. I am not able to use serial bootloader to download cc26xx-web-demo.bin to your LAUNCHXL-CC1310 even after i did the mass erase to LAUNCHXL-CC1310.
The status reply is:

>Initiate access to target: COM5.
>No response from device. Device may not be in bootloader mode. Reset device and try again.
If problem persists, check connection and baud rate.
>Connecting over serial bootloader failed: No response from device. Device may not be in bootloader mode. Reset device and try again.
If problem persists, check connection and baud rate.
>Failed to create device object.

Not sure why it fails.

Could you post screenshots of what you do step by step?

Do you select the device to CC1310F128 before you do connect to it?

Yes sir.

Could you post screenshots of what you do step by step?

I followed the following steps:

1. Cloned a fresh contiki on my PC using the command:

git clone --recursive github.com/.../contiki

git submodule synch && git submodule update --init

2. Modified the ccfg.c file at the following locations

i. contiki/cpu/cc26xx-13xx/lib/cc13xxware/startup_files

ii.contiki/cpu/cc26xx-13xx/lib/cc26xxware/startup_files

3. At contiki/examples/cc26xx/cc26xx-web-demo, generated the .bin file by using the command:

make TARGET=srf06-cc26xx BOARD=launchpad/cc1310 cc26xx-web-demo.bin

4. Forced Mass erase as shown in the image:

5. Selected the chip as CC1310F128. Tried connecting to the UART. Status says failed as in the following image: 

6. Then I flashed CC26xx-demo-bin to the board which was successful. Indicated by the blinking of the green light (DIO7) on CC1310 launchpad.

7. Connected the DIO11 pin to Ground. Reset the system.  Tried connecting the Board to UART. It failed again. 

Please let me what am I doing incorrectly here. and what more should I try?

After step5, I suppose you need to right click on cc1310f128 to connect to device first. Then, you can start to download cc26xx-web-demo.bin

Yes, sir. By connecting I mean the same, right click on the cc1310f128 to connect to the device. That's where the connection fails. 

If I select cc1310(top-most option), I am able to flash the microcontroller. But that's not what I want. 

The jumper for the Rxd pins were not mounted. Because of which i was not able to receive the acknowledgment. But now I am able to enter the bootloader and perform the flash.
Thank you so much for resolving the issue.
Sorry for all the trouble.