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Joseph.Paul
Associate II
Apr 22, 2024 5:54 PM UTC
Question

STM32H747 DMA Memory Size?

Per spec. STM32H747 has 1MB on-chip memory available. However, how that memory mapped is something I don't quite know. Linker allocates 256K @ 0x2000000 for code, and there's some DMA memory @ 0xD000000, but it's size is mystery as there's no explicit definitions for it.

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2 replies

AScha.3
Super User
Apr 22, 2024 6:12 PM UTC

The H747 has 

AScha3_0-1713809144530.png

The address you can read in rm , if you like :

AScha3_1-1713809291670.png

-> see rm for your chip

DMA can access all memory, but not in one dma transfer, 65K limit, just look in rm :

AScha3_2-1713809442739.png

 

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Tesla DeLorean
Guru
Apr 22, 2024 6:24 PM UTC

It's a transaction size, could be 65535 * 32-bit words, and perhaps has a double buffer model so can ping-pong between two such buffers.

Ideal situation you're not moving that much data around, or there are better ways to manage it.

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