SPRUIW9C October 2021 – March 2024 TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1
The HIC does not require all pins for operation. The following describes use-cases for a reduced set of pins.
Read/Write Control Pins
Controlling read/write can be achieved using just one pin, nOE/RnW pin, instead of the traditional two pins: nOE and nWE pins. Configuration is achieved through the HICMODECR.RW_MODE register. See Section 14.3.3 for details.
BASESEL Pins
If no BASESEL pins are available, the HIC is restricted to mailbox access mode where the external host can only access the HIC memory mapped registers. However to access device registers through direct access mode, only one BASESEL pin is required.
In this configuration, the BASESEL0 pin determines whether the access being made is mailbox access or direct access. BASESEL0 set to 0 is a mailbox access; BASESEL0 set to 1 is a direct access. This configuration restricts base address selection to only HICDBADDR0. Configuration is achieved through the HICHOSTCR.PAGESEL register. See Section 14.3.2.1 for details.
Data Pins
The HIC supports 8-bit and 16-bit transfers. 16-bit data transfers can still be achieved with 8 data lines. This is handled internally by the HIC through data packing and unpacking. See Section 14.3.4 for details.
Byte-Enable Pins
If no byte-enable pins are available, the HIC defaults to 16-bit data transfers but can be re-configured using the HICMODECR.DW_MODE register. Configuration is achieved through the HICMODECR.BEN_PRESENT register. See Section 14.3.4 for details.
Ready Pin
If no nRDY pin is available, the host must add sufficiently large setup/hold times during data transmission to prevent clashes. Configuration is achieved through the HICMODECR.RDY_PRESENT register.