DMA controller (DMA)
RM0090
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DocID018909 Rev 11
10.3.4 Arbiter
An arbiter manages the 8 DMA stream requests based on their priority for each of the two
AHB master ports (memory and peripheral ports) and launches the peripheral/memory
access sequences.
Priorities are managed in two stages:
•
Software: each stream priority can be configured in the DMA_SxCR register. There are
four levels:
–
Very high priority
–
High priority
–
Medium priority
–
Low priority
•
Hardware: If two requests have the same software priority level, the stream with the
lower number takes priority over the stream with the higher number. For example,
Stream 2 takes priority over Stream 4.
Channel 6
TIM5_CH3
TIM5_UP
TIM5_CH4
TIM5_TRIG
TIM5_CH1
TIM5_CH4
TIM5_TRIG
TIM5_CH2
TIM5_UP
Channel 7
TIM6_UP
I2C2_RX
I2C2_RX
USART3_TX
DAC1
DAC2
I2C2_TX
1. These requests are available on STM32F42xxx and STM32F43xxx only.
Table 42. DMA1 request mapping (continued)
Peripheral
requests
Stream 0
Stream 1
Stream 2
Stream 3
Stream 4
Stream 5
Stream 6
Stream 7
Table 43. DMA2 request mapping
Peripheral
requests
Stream 0
Stream 1
Stream 2
Stream 3
Stream 4
Stream 5
Stream 6
Stream 7
Channel 0
ADC1
SAI1_A
TIM8_CH1
TIM8_CH2
TIM8_CH3
SAI1_A
ADC1
SAI1_B
TIM1_CH1
TIM1_CH2
TIM1_CH3
Channel 1
DCMI
ADC2
ADC2
SAI1_B
SPI6_TX
SPI6_RX
DCMI
Channel 2
ADC3
ADC3
SPI5_RX
(1)
SPI5_TX
CRYP_OUT
CRYP_IN
HASH_IN
Channel 3
SPI1_RX
SPI1_RX
SPI1_TX
SPI1_TX
Channel 4
SPI4_RX
SPI4_TX
USART1_RX
SDIO
USART1_RX
SDIO
USART1_TX
Channel 5
USART6_RX
USART6_RX
SPI4_RX
SPI4_TX
USART6_TX
USART6_TX
Channel 6
TIM1_TRIG
TIM1_CH1
TIM1_CH2
TIM1_CH1
TIM1_CH4
TIM1_TRIG
TIM1_COM
TIM1_UP
TIM1_CH3
Channel 7
TIM8_UP
TIM8_CH1
TIM8_CH2
TIM8_CH3
SPI5_RX
SPI5_TX
TIM8_CH4
TIM8_TRIG
TIM8_COM
1. These requests are available on STM32F42xxx and STM32F43xxx.