RTOS/CC2640R2F: CC2640R2F ON CHIP OAD

Tool/software: TI-RTOS

Hi,

I am working on CC2640R2F on chip OAD.software is CCS v7 and simplink_cc2640r2_sdk_1_50_00_58.

hardware is CC2640R2 development and cc2540 usb dongle.

I did test as folowing steps:

1,Import projects in folder "simple_peripheral_oad_onchip" to ccs v7.

2,Build the 4 projects(bim..., persisten...,oad.., oad_stack).

3,Program 4 HEX files(bim_oad_onchip_cc2640r2lp_app.hex,persistent_app_cc2640r2lp_flashonly.hex,simple_peripheral_cc2640r2lp_oad_onchip_app_flashrom.hex,simple_peripheral_cc2640r2lp_oad_onchip_stack_flashrom.hex).

to cc2640r2 development board with flash programmer2.

4,Then on ble device monitor ,I found the device as "OAD Persistent APP".

5,I tried to OAD the file of "simple_peripheral_cc2640r2lp_oad_onchip_app_flashrom_oad.bin" ,but it stopped  after a few transfers.

my questions:

1.my understanding is after step 3,I would found the device as "SBP OAD APP v  ",but now is"OAD Persistent APP",it seems that  the bim select persistent program but not the simple_peripheral_app to run, why?

2,where is the issue of OAD failed?

thanks