Timx Dma Control Register (Timx_Dcr); Timx Dma Address For Full Transfer (Timx_Dmar) - ST STM32F40 Series Reference Manual

General-purpose timers (TIM2 to TIM5)
15.4.17

TIMx DMA control register (TIMx_DCR)

Address offset: 0x48
Reset value: 0x0000
15 14 13
Reserved
Bits 15:13 Reserved, must be kept at reset value.
Bits 12:8 DBL[4:0]: DMA burst length
Bits 7:5 Reserved, must be kept at reset value.
Bits 4:0 DBA[4:0]: DMA base address
Example: Let us consider the following transfer: DBL = 7 transfers & DBA = TIMx_CR1. In this
case the transfer is done to/from 7 registers starting from the TIMx_CR1 address.
15.4.18

TIMx DMA address for full transfer (TIMx_DMAR)

Address offset: 0x4C
Reset value: 0x0000
15 14 13
rw rw rw
Bits 15:0 DMAB[15:0]: DMA register for burst accesses
477/1422
12 11 10 9
DBL[4:0]
rw rw rw rw
This 5-bit vector defines the number of DMA transfers (the timer recognizes a burst transfer
when a read or a write access is done to the TIMx_DMAR address).
00000: 1 transfer,
00001: 2 transfers,
00010: 3 transfers,
...
10001: 18 transfers.
This 5-bit vector defines the base-address for DMA transfers (when read/write access are
done through the TIMx_DMAR address). DBA is defined as an offset starting from the
address of the TIMx_CR1 register.
Example:
00000: TIMx_CR1,
00001: TIMx_CR2,
00010: TIMx_SMCR,
...
12 11 10 9
rw rw rw rw
A read or write operation to the DMAR register accesses the register located at the address
(TIMx_CR1 address) + (DBA + DMA index) x 4
where TIMx_CR1 address is the address of the control register 1, DBA is the DMA base
address configured in TIMx_DCR register, DMA index is automatically controlled by the DMA
transfer, and ranges from 0 to DBL (DBL configured in TIMx_DCR).
Doc ID 018909 Rev 4
8 7 6 5
Reserved
rw
8 7 6 5
DMAB[15:0]
rw rw rw rw
4 3 2 1
DBA[4:0]
rw rw rw rw
4 3 2 1
rw rw rw rw
RM0090
0
rw
0
rw