Currently when Ibex sees an integrity check failure on incoming memory request responses it triggers a major alert but the core still accepts the data and will continue executing until the major alert causes some action.

The integrity check occur one cycle after the response is received. We could move it to the same cycle the response is received so it could generate an error response if the check fails. This seems like better behaviour. There's a chance it'll cause timing issues but I don't think it's a worry as the ECC error check is a handful of logic levels.