SPRUJD4A December 2024 – November 2025 AM62D-Q1
AM62D has one single R5F core in the wakeup domain. The R5F is a native 32b processor, which the R5F core itself can only generate transactions using 32b address. A dedicated RAT module is integrated for this single core R5F to allow the R5F software to remap the 32b R5F address into the common 36b SoC address.
In addition, the R5F core has its own TCM, which the R5F core can access with its TCM with a single R5F core cycle. Those TCM memories have two sets of address, one set address is used for the R5F core for a single cycle access to those TCM. The second set of address is used by other initiators outside this R5F subsystem to access those TCM. The R5F core shall always use the first set of address to access its TCM. If the R5F core utilizes the second set of address to those TCM, the R5F core will receives an exception, since those transactions will be routed to be terminated by sending them to the null end point.
While the SoC level address for TCM is fixed, the address used by the R5F to access to its own TCM can be remapped by software. By default, AM62D puts the R5F’s ATCM at address 0x0 and the BTCM address at 0x4101_0000.
The R5F also has one section of the region dedicated for peripheral access from address 0x0400_0000 to 0x07FF_FFFF. This memory region is treated as normally memory, which can’t be cached. The R5F accesses this memory region through a dedicated single-issue interface, and none of the transactions accessing this memory region can be remapped by using RAT module.
The R5F core accesses its own ATCM and BTCM memory directly, and there is no address remapping for those access. All the other access than ATCM, BTCM and address range 0x0400_0000 to 0x07FF_FFFF from the R5F core go through RAT module, which could be remapped into different address to access the rest of the SoC using the common 36b SoC memory map.
| Base Address | Size | Memory Region | Additional Note |
|---|---|---|---|
| 0000_0000 | 32KB | ATCM | The R5F can re-map its ATCM to a different address internally. After the R5F re-maps its ATCM address, any transaction hitting this region can also go through RAT remapping function. |
| 0000_8000 | 64MB-32KB | RAT_region0 | |
| 0400_0000 | 64M-128K | Non_RAT region | |
| 07FE_0000 | 4K | RAT_CFG | This is within the non_RAT region |
| 07FF_0000 | 16K | VIM_CFG | This is within the non_RAT region |
| 0800_0000 | 912MB+64KB | RAT_region1 | |
| 4101_0000 | 32KB | BTCM | The R5F can re-map its BTCM to a different address internally. After the R5F re-maps its ATCM address, any transaction hitting this region can also go through RAT remapping function. |
| 4101_8000 | 1GB-16480K | RAT_Region2 | |
| 8000_0000 | 2GB | RAT_Region3 |
The common SoC memory map assigns the R5F’s ATCM and BTCM to address 0x7900_0000 and 0x7902_0000. The R5F software can optionally reprogram the its internal ATCM and BTCM address to match the address assigned by the common SoC memory map as well. Regardless where the R5F puts its own ATCM and BTCM, the R5F accesses its own ATCM and BTCM directly without going through RAT.
ATCM is by default disabled at address 0x0. BTCM is by default enabled and the default address for BTCM is 0x4101_0000. The base address of VIM is at 0x07FF_0000 and the base address for RAT configuration is at 0x07FE_0000.
All the R5F transactions can go through RAT for address re-mapping function except the transactions targeted to address range 0x0400_0000 to 0x07FF_FFFF and its own ATCM and BTCM. It is highly recommended only remap the R5F’s address range from 0x8000_0000 to 0xFFFF_FFFF to access the target region located at the common memory map between 0x8000_0000 and 0xF_FFFF_FFFF.