4.1 Introduction
The EFR32 contains an AMBA AHB Bus system to allow bus masters to access the memory mapped address space. A multilayer AHB
bus matrix connects the 5 master bus interfaces to the AHB slaves (
Figure 4.1 EFR32 Bus System on page 42
). The bus matrix al-
lows several AHB slaves to be accessed simultaneously. An AMBA APB interface is used for the peripherals, which are accessed
through an AHB-to-APB bridge connected to the AHB bus matrix. The 5 AHB bus masters are:
•
Cortex-M4 ICode:
Used for instruction fetches from Code memory (valid address range: 0x00000000 - 0x1FFFFFFF)
•
Cortex-M4 DCode:
Used for debug and data access to Code memory (valid address range: 0x00000000 - 0x1FFFFFFF)
•
Cortex-M4 System:
Used for data and debug access to system space. It can access entire memory space except Code memory
(valid address range: 0x20000000 - 0xFFFFFFFF)
•
DMA:
Can access the entire memory space except the internal core memory region and the DMEM code region
•
Sequencer Code:
Used for instruction fetches and data accesses. Instruction fetches still come from data memory. (valid address
range: 0x00000000 - 0x0FFFFFFF, 0x20000000 - 0x3FFFFFFF)
•
Sequencer System:
Can access entire memory space except internal core memory region and RAM code space (valid address
range: 0x00000000 - 0x0FFFFFFF, 0x20000000 - 0xDFFFFFFF)
•
BUFC:
Can access general purpose SRAM (valid address range: 0x20000000 - 0x20FFFFFF)
•
FRC:
Can access general purpose SRAM (valid address range: 0x20000000 - 0x20FFFFFF)
Cortex-M
AHB Multilayer
Bus Matrix
DCode
System
ICode
DMA
Sequencer
Code
System
FRC
BUFC
Flash
RAM0
AHB/APB
Bridge
CRYPTO
Peripheral n
RAMn
SEQ_RAM
Peripheral 0
Figure 4.1. EFR32 Bus System
Reference Manual
Memory and Bus System
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