SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The AXI input is driven from the single external port of the L2 cache. The incoming accesses are directed to the MPU_AXI2OCP module through the A2O port or begin their processing for a potential EMIF access. The routing of accesses is based on the AXI address and the EMIF boot input (pi_emifboot).
Table 4-2 lists the AXI access memory mapping. If the accesses are targeted for the MPU_AXI2OCP, then they are registered and sent to the A2O port without any alterations in its attributes (size, ID, etc.). The reserved space in the lower order memory area is a result of providing 8 GiB of continuous space for all the nonaliased regions.
The EMIF memory space is broken into eight 1-GiB sections, which are denoted emif(a) through emif(h). This partitioning helps to specify the aliasing of several memory ranges. It also aids in the discussion of how the MPU memory space is mapped into the physical EMIF space.
Although the MPU has 8-GiB EMIF dedicated memory space, only 4 GiB are used. 4 GiB is the total of physically available SDRAM for this device.
It is expected that the OS uses either the lower 2-GiB space and the lower aliased address of emif(a) and (b), or the continuous 8-GiB space and the upper aliasing of the emif(a) and (b) for all EMIF accesses.
Region Name | Start Address | End Address | Interleaving | MPU_MA Action |
---|---|---|---|---|
Boot space | 0x00 0000 0000 | 0x00 000F FFFF | Default | Sent to Firewall/EMIF, if pi_emifboot = 1 |
N/A | Sent to A2O port, if pi_emifboot = 0 | |||
Non-emif | 0x00 0010 0000 | 0x00 7FFF FFFF | N/A | Sent to A2O port |
Emif(a) | 0x00 8000 0000 | 0x00 BFFF FFFF | Programmable | Aliased to address range 0x02 8000 0000–0x02 FFFF FFFF |
Emif(b) | 0x00 C000 0000 | 0x00 FFFF FFFF | Programmable | |
Reserved | 0x01 0000 0000 | 0x01 FFFF FFFF | N/A | DECERR returned |
Emif(c) | 0x02 0000 0000 | 0x02 3FFF FFFF | Fixed | Sent to Firewall/EMIF |
Emif(d) | 0x02 4000 0000 | 0x02 7FFF FFFF | Fixed | Sent to Firewall/EMIF |
Emif(a) | 0x02 8000 0000 | 0x02 BFFF FFFF | Programmable | Sent to Firewall/EMIF |
Emif(b) | 0x02 C000 0000 | 0x02 FFFF FFFF | Programmable | Sent to Firewall/EMIF |
Emif(g) | 0x03 0000 0000 | 0x03 3FFF FFFF | Fixed | Sent to Firewall/EMIF |
Emif(h) | 0x03 4000 0000 | 0x03 7FFF FFFF | Fixed | Sent to Firewall/EMIF |
Emif(e) | 0x03 8000 0000 | 0x03 BFFF FFFF | Fixed | Sent to Firewall/EMIF |
Emif(f) | 0x03 C000 0000 | 0x03 FFFF FFFF | Fixed | Sent to Firewall/EMIF |
Reserved | 0x04 0000 0000 | 0xFF FFFF FFFF | N/A | DECERR returned |