7 Custom Extensions

Any custom CTR extension must be associated with a non-zero value within the designated custom bits in _x_ctrctl. When the custom bits hold a non-zero value that enables a custom extension, the extension may alter standard CTR behavior, and may define new custom status fields within sctrstatus or the CTR Entry Registers. All custom status fields, and standard status fields whose behavior is altered by the custom extension, must revert to standard behavior when the custom bits hold zero. This includes read-only 0 behavior for any bits undefined by any implemented standard extensions.