SPRUIN7C March 2020 – March 2024 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1
To place the HIC in Mailbox Access Mode, the BASESEL[2:0] pins must be set to 000. Address lines A[7:0] can then be used to select which of the 256 bytes of the HIC memory-mapped registers to access.