Multichip Memory Map(s)

Introduction

In a multichip chip platform. One of the chip is identified as primary chip and the other three as secondary chip. Each chip is allocated a different address region in the system memory map. The CMN interconnect on each chip is programmed with its own RN-SAM at boot time.

• The PCIe ECAM/MMIO regions are split across multiple chips by configuring the CMN RN-SAM.

• The DRAM memory regions are split across multiple chips by configuring the CMN RN-SAM.

Reference Memory Map

In a multichip platform, the per chip address size for peripherals is 64GB, and the base address for peripherals residing in each chip are:

Start Addr	End Addr	Size	Chiplet
0x00_0000_0000	0x0F_FFFF_FFFF	64 GB	Chip0 Onchip Peripheral space base address
0x10_0000_0000	0x1F_FFFF_FFFF	64 GB	Chip1 Onchip Peripheral space base address
0x20_0000_0000	0x2F_FFFF_FFFF	64 GB	Chip2 Onchip Peripheral space base address
0x30_0000_0000	0x3F_FFFF_FFFF	64 GB	Chip3 Onchip Peripheral space base address
0x40_0000_0000	0xFFFF_FFFF_FFFF	255.75 TB	Can be mapped to any chiplet

Interrupt Map

On the shared peripheral interrupt (SPI), each chip are assigned with 480 SPIs. The SPI mappings are:

Chiplet	SPI ID mapping
Chip0	32 - 511
Chip1	512 - 991
Chip2	4096 - 4575
Chip3	4576 - 5055

DRAM Map

Each chip of a multichip FVP is equiped with two DRAM blocks, a 2GB and a 6GB. The 6GB DRAM of the secondary chips are kept outside of the 64GB address per chip. The DRAM mappings are:

RD-V3-Cfg2

Chiplet	Size	Start Addr	End Addr
Chip0	2GB	0x0000_8000_0000	0x0000_FFFF_FFFF
Chip0	6GB	0x0080_8000_0000	0x0081_FFFF_FFFF
Chip1	2GB	0x0010_8000_0000	0x0010_FFFF_FFFF
Chip1	6GB	0x2080_8000_0000	0x2081_FFFF_FFFF
Chip2	2GB	0x0020_8000_0000	0x0020_FFFF_FFFF
Chip2	6GB	0x3080_8000_0000	0x3081_FFFF_FFFF
Chip3	2GB	0x0030_8000_0000	0x0030_FFFF_FFFF
Chip3	6GB	0x4080_8000_0000	0x4081_FFFF_FFFF

RD-V3-R1

Chiplet	Size	Start Addr	End Addr
Chip0	2GB	0x0000_8000_0000	0x0000_FFFF_FFFF
Chip0	6GB	0x0200_8000_0000	0x0201_FFFF_FFFF
Chip1	2GB	0x0010_8000_0000	0x0010_FFFF_FFFF
Chip1	6GB	0x0300_8000_0000	0x0301_FFFF_FFFF

RD-V3-R1-Cfg1

Chiplet	Size	Start Addr	End Addr
Chip0	2GB	0x0000_8000_0000	0x0000_FFFF_FFFF
Chip0	6GB	0x0200_8000_0000	0x0201_FFFF_FFFF
Chip1	2GB	0x0010_8000_0000	0x0010_FFFF_FFFF
Chip1	6GB	0x0300_8000_0000	0x0301_FFFF_FFFF
Chip2	2GB	0x0020_8000_0000	0x0020_FFFF_FFFF
Chip2	6GB	0x0400_8000_0000	0x0401_FFFF_FFFF
Chip3	2GB	0x0030_8000_0000	0x0030_FFFF_FFFF
Chip3	6GB	0x0500_8000_0000	0x0501_FFFF_FFFF