DocID018909 Rev 11
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RM0090
Memory and bus architecture
112
In the STM32F42xx and STM32F43xx devices, the main system consists of 32-bit multilayer
AHB bus matrix that interconnects:
•
Ten masters:
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Cortex
®
-M4 with FPU core I-bus, D-bus and S-bus
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DMA1 memory bus
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DMA2 memory bus
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DMA2 peripheral bus
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Ethernet DMA bus
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USB OTG HS DMA bus
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LCD Controller DMA-bus
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DMA2D (Chrom-Art Accelerator™) memory bus
•
Eight slaves:
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Internal Flash memory ICode bus
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Internal Flash memory DCode bus
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Main internal SRAM1 (112 KB)
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Auxiliary internal SRAM2 (16 KB)
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Auxiliary internal SRAM3 (64 KB)
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AHB1peripherals including AHB to APB bridges and APB peripherals
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AHB2 peripherals
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FMC
The bus matrix provides access from a master to a slave, enabling concurrent access and
efficient operation even when several high-speed peripherals work simultaneously. The 64-
Kbyte CCM (core coupled memory) data RAM is not part of the bus matrix and can be
accessed only through the CPU. This architecture is shown in
.