SPRUIM2H May 2020 – October 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442
The address location is the initial address that will be accessed at the start of the transfer. All of the dimensions will also be based off of this value. This address can either physical or virtual based upon settings in the DMA channel Configuration register.
While the ADDR field is 64 bits wide, the usable extent of the address is up to 48 bits of absolute offset plus a 4-bit address space selector which indicates 1 of 16 different orthogonal address spaces that the pointer is referencing within. The format of the ADDR field is given as follows:
Bits |
Subfield |
Description |
---|---|---|
63:52 |
Reserved |
Reserved |
51:48 |
Address Space Select |
Effectively bits 51:48 of the address. The value given in this field will be output by the DMA initiators on the casel pin which is used by the infrastructure as an identifier for which address space this particular memory region is located within. Address space 0 is the default unified address space for a given device. Address spaces 1-15 are used for alternate address maps which may be external to the device (PCIe/Hyperlink) or in other ‘tiles’ on large devices. |
47:0 |
Address |
The 48-bit source or source starting address for the transfer. This address is assumed to be a physical address. The actual width implemented for the address field on any given DMA instance may be adjusted to the needs of each specific KSLC SoC. 48 bits is just the maximum size which is envisioned to be supported. Some systems may have address widths as low as 32 or 36 bits. The HW implementation may choose to provide address width configurability in order to reduce costs. |