Does DID amnesia result from trauma or intrusive memory

This issue has been discussed in another thread dissociative-amnesia/topic125932.html but I think has particular significance to DID. I'm thinking that in cases of incest and child sexual abuse where the abuse occurs over an extended period of time, the amnesia doesn't occur contemporaneously with the abuse or even directly as a result of the abuse, but instead as the result of intrusive memories which develop following the abuse.

Does anyone have insight into this or seen this discussed in the literature?

I don't know how it happened to others but I know that my childhood amnesia was by choice.
I simply pushed the bad memories out of reach and kept them there, I became so used at keeping them at bay that it became an automatic action , much like breathing or blinking , and after a while I fergot about it completely.