Datasheet

Functional overview STM32F20xxx
20/178 DocID15818 Rev 11
Figure 5. Multi-AHB matrix
3.8 DMA controller (DMA)
The devices feature two general-purpose dual-port DMAs (DMA1 and DMA2) with 8
streams each. They are able to manage memory-to-memory, peripheral-to-memory and
memory-to-peripheral transfers. They share some centralized FIFOs for APB/AHB
peripherals, support burst transfer and are designed to provide the maximum peripheral
bandwidth (AHB/APB).
The two DMA controllers support circular buffer management, so that no specific code is
needed when the controller reaches the end of the buffer. The two DMA controllers also
have a double buffering feature, which automates the use and switching of two memory
buffers without requiring any special code.
Each stream is connected to dedicated hardware DMA requests, with support for software
trigger on each stream. Configuration is made by software and transfer sizes between
source and destination are independent.
ARM
Cortex-M3
GP
DMA1
GP
DMA2
MAC
Ethernet
USB OTG
HS
Bus matrix-S
S0 S1 S2 S3 S4 S5 S6 S7
ICODE
DCODE
ART
ACCEL.
Flash
memory
SRAM
112 Kbyte
SRAM
16 Kbyte
AHB1
periph
AHB2
periph
FSMC
Static MemCtl
M0
M1
M2
M3
M4
M5
M6
I-bus
D-bus
S-bus
DMA_P1
DMA_MEM1 DMA_MEM2
DMA_P2
ETHERNET_M
USB_HS_M
ai15963c
APB1
APB2