Internal Rom; Embedded Memory Address Mapping - Espressif Systems ESP32 Technical Reference Manual

1.3 Functional Description
Bus Type
Low Address
Data 0x3FF8_0000
0x3FF8_2000
Data 0x3FF9_0000
0x3FFA_0000
Data 0x3FFA_E000
Data 0x3FFE_0000
Bus Type
Low Address
Instruction 0x4000_0000
Instruction 0x4000_8000
0x4006_0000
Instruction 0x4007_0000
Instruction 0x4008_0000
Instruction 0x400A_0000
Instruction 0x400B_0000
Instruction 0x400B_8000
Instruction 0x400C_0000
Bus Type
Low Address
Data Instruc-
0x5000_0000
tion

1.3.2.1 Internal ROM 0

The capacity of Internal ROM 0 is 384 KB, It is accessible by both CPUs through the address range
0x4000_0000 ~ 0x4005_FFFF, which is on the instruction bus.
The address range of the first 32 KB of the ROM 0 (0x4000_0000
a part of Internal SRAM 1 that normally resides in the memory range 0x400B_0000
While remapping, such 32 KB SRAM can not be accessed by address range 0x400B_0000
more, but it can still be accessible through the data bus (0x3FFE_8000
per-CPU basis: setting bit 0 of register DPORT_PRO_BOOT_REMAP_CTRL_REG or
DPORT_APP_BOOT_REMAP_CTRL_REG will remap SRAM for the PRO_CPU and APP_CPU,
respectively.
1.3.2.2 Internal ROM 1
The capacity of Internal ROM 1 is 64 KB. It can be read by either CPU at address range 0x3FF9_0000
0x3FF9_FFFF of the data bus.
Espressif Systems
Table 2: Embedded Memory Address Mapping
Boundary Address
High Address
0x3FF8_1FFF
0x3FF8_FFFF
0x3FF9_FFFF
0x3FFA_DFFF
0x3FFD_FFFF
0x3FFF_FFFF
Boundary Address
High Address
0x4000_7FFF
0x4005_FFFF
0x4006_FFFF
0x4007_FFFF
0x4009_FFFF
0x400A_FFFF
0x400B_7FFF
0x400B_FFFF
0x400C_1FFF
Boundary Address
High Address
0x5000_1FFF
Size Target
8 KB RTC FAST Memory
56 KB Reserved
64 KB Internal ROM 1
56 KB Reserved
200 KB Internal SRAM 2
128 KB Internal SRAM 1
Size Target
32 KB Internal ROM 0
352 KB Internal ROM 0
64 KB Reserved
64 KB Internal SRAM 0
128 KB Internal SRAM 0
64 KB Internal SRAM 1
32 KB Internal SRAM 1
32 KB Internal SRAM 1
8 KB RTC FAST Memory
Size Target
8 KB RTC SLOW Memory
~ 0x4000_7FFF) can be re-mapped to access
~ 0x3FFE_FFFF). This can be done on a
11 ESP32 Technical Reference Manual V1.0
1 SYSTEM AND MEMORY
Comment
PRO_CPU Only
-
-
-
DMA
DMA
Comment
Remap
-
-
Cache
-
-
Remap
-
PRO_CPU Only
Comment
-
~ 0x400B_7FFF instead.
~
0x400B_7FFF any
~