ST STM32F40 Series

RM0090 DMA controller (DMA)
Doc ID 018909 Rev 4 244/1422
9.5.10 DMA stream x FIFO control register (DMA_SxFCR) (x = 0..7)
Address offset: 0x24 + 0x24 × stream number
Reset value: 0x0000 0021
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
Reserved
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Reserved
FEIE
Reser
ved
FS[2:0] DMDIS FTH[1:0]
rw r r r rw rw rw
Bits 31:8 Reserved, must be kept at reset value.
Bits 7 FEIE: FIFO error interrupt enable
This bit is set and cleared by software.
0: FE interrupt disabled
1: FE interrupt enabled
Bits 6 Reserved, must be kept at reset value.
Bits 5:3 FS[2:0]: FIFO status
These bits are read-only.
000: 0 < fifo_level < 1/4
001: 1/4 ≤ fifo_level < 1/2
010: 1/2 ≤ fifo_level < 3/4
011: 3/4 ≤ fifo_level < full
100: FIFO is empty
101: FIFO is full
others: no meaning
These bits are not relevant in the direct mode (DMDIS bit is zero).
Bits 2 DMDIS: Direct mode disable
This bit is set and cleared by software. It can be set by hardware.
0: Direct mode enabled
1: Direct mode disabled
This bit is protected and can be written only if EN is ‘0’.
This bit is set by hardware if the memory-to-memory mode is selected (DIR bit in
DMA_SxCR are “10”) and the EN bit in the DMA_SxCR register is ‘1’ because the direct
mode is not allowed in the memory-to-memory configuration.
Bits 1:0 FTH[1:0]: FIFO threshold selection
These bits are set and cleared by software.
00: 1/4 full FIFO
01: 1/2 full FIFO
10: 3/4 full FIFO
11: full FIFO
These bits are not used in the direct mode when the DMIS value is zero.
These bits are protected and can be written only if EN is ‘1’.