(Original) Why won't the software program be moved after the niosii reset? (IC design) (de2)

Abstract
The program of niosii is normal, but after reset, the program will not be moved. How can this problem be solved?

Environment: US us II 7.2 SP1 + niosii 7.2 SP1 + de2 (Cyclone II ep2c35f627c6)

Introduction
I used a program that runs on-chip memory on niosii. No matter how many Resets are normal, but after I run the SRAM, I only need to press Key [0] reset, the software program will not be moved. How can we solve this problem?

Solution
The following settings are available for the nio ii processor in the System Builder:

1. Use the nio ii/F
When the program runs on-chip memory, the result of the selection of the niosii/e, niosii/s, or niosii/F does not appear, however, if you are running on the SRAM, You must select the niosii/F option to continue running normally.

2. Set the Reset vector in the SRAM
Because the reference design of de2 sets the Reset vector to flash, if the Reset vector is not modified, the reset SRAM cannot be reset when the reset is pressed, so we need to change the Reset vector to the SRAM.

Conclsion
Why must I select niosii/F? I do not know the reason at present. If you have any idea, please let us know.