ST STM32WL55JC Reference Manual page 938

General-purpose timers (TIM16/TIM17)
Bits 15:13 Reserved, must be kept at reset value.
Bits 12:8 DBL[4:0]: DMA burst length
This 5-bit field defines the length of DMA transfers (the timer recognizes a burst transfer
when a read or a write access is done to the TIMx_DMAR address), i.e. the number of
transfers. Transfers can be in half-words or in bytes (see example below).
00000: 1 transfer,
00001: 2 transfers,
00010: 3 transfers,
...
10001: 18 transfers.
Bits 7:5 Reserved, must be kept at reset value.
Bits 4:0 DBA[4:0]: DMA base address
This 5-bit field 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,
...
Example: Let us consider the following transfer: DBL = 7 transfers and DBA = TIMx_CR1. In
this case the transfer is done to/from 7 registers starting from the TIMx_CR1 address.
27.4.16 TIMx DMA address for full transfer (TIMx_DMAR)(x = 16 to 17)
Address offset: 0x4C
Reset value: 0x0000
15 14 13
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Bits 15:0 DMAB[15:0]: DMA register for burst accesses
A read or write operation to the DMAR register accesses the register located at the address
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).
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12 11 10 9
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(TIMx_CR1 address) + (DBA + DMA index) x 4
8 7 6
DMAB[15:0]
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RM0453 Rev 2
5 4 3 2
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RM0453
1 0
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