STMicroelectronics /STM32U585 /GPDMA1 /GPDMA_C12BR1

block number of data bytes to transfer from the source Block size transferred from the source. When the channel is enabled, this field becomes read-only and is decremented, indicating the remaining number of data items in the current source block to be transferred. BNDT[15:0] is programmed in number of bytes, maximum source block size is 64 Kbytes -1. Once the last data transfer is completed (BNDT[15:0] = 0):

• if GPDMA_CxLLR.UB1 = 1, this field is updated by the LLI in the memory.
• if GPDMA_CxLLR.UB1 = 0 and if there is at least one not null Uxx update bit, this field is internally restored to the programmed value.
• if all GPDMA_CxLLR.Uxx = 0 and if GPDMA_CxLLR.LA[15:0] ≠ 0, this field is internally restored to the programmed value (infinite/continuous last LLI).
• if GPDMA_CxLLR = 0, this field is kept as zero following the last LLI data transfer. Note: A non-null source block size must be a multiple of the source data width (BNDT[2:0] versus GPDMA_CxTR1.SDW_LOG2[1:0]). Else a user setting error is reported and no transfer is issued. When configured in packing mode (GPDMA_CxTR1.PAM[1]=1 and destination data width different from source data width), a non-null source block size must be a multiple of the destination data width (BNDT[2:0] versus GPDMA_CxTR1.DDW_LOG2[1:0]). Else a user setting error is reported and no transfer is issued.

Block repeat counter This field contains the number of repetitions of the current block (0 to 2047). When the channel is enabled, this field becomes read-only. After decrements, this field indicates the remaining number of blocks, excluding the current one. This counter is hardware decremented for each completed block transfer. Once the last block transfer is completed (BRC[10:0] = BNDT[15:0] = 0): If GPDMA_CxLLR.UB1 = 1, all GPDMA_CxBR1 fields are updated by the next LLI in the memory. If GPDMA_CxLLR.UB1 = 0 and if there is at least one not null Uxx update bit, this field is internally restored to the programmed value. if all GPDMA_CxLLR.Uxx = 0 and if GPDMA_CxLLR.LA[15:0] ≠ 0, this field is internally restored to the programmed value (infinite/continuous last LLI). if GPDMA_CxLLR = 0, this field is kept as zero following the last LLI and data transfer.

source address decrement

0 (B_0x0): At the end of a programmed burst transfer from the source, the GPDMA_CxSAR register is updated by adding the programmed offset GPDMA_CxTR3.SAO to the current GPDMA_CxSAR value (current source address)

1 (B_0x1): At the end of a programmed burst transfer from the source, the GPDMA_CxSAR register is updated by subtracting the programmed offset GPDMA_CxTR3.SAO to the current GPDMA_CxSAR value (current source address)

destination address decrement

0 (B_0x0): At the end of a programmed burst transfer to the destination, the GPDMA_CxDAR register is updated by adding the programmed offset GPDMA_CxTR3.DAO to the current GPDMA_CxDAR value (current destination address)

1 (B_0x1): At the end of a programmed burst transfer to the destination, the GPDMA_CxDAR register is updated by subtracting the programmed offset GPDMA_CxTR3.DAO to the current GPDMA_CxDAR value (current destination address)

Block repeat source address decrement Note: On top of this increment/decrement (depending on BRSDEC), GPDMA_CxSAR is in the same time also updated by the increment/decrement (depending on SDEC) of the GPDMA_CxTR3.SAO value, as it is done after any programmed burst transfer.

0 (B_0x0): at the end of a block transfer, the GPDMA_CxSAR register is updated by adding the programmed offset GPDMA_CxBR2.BRSAO to the current GPDMA_CxSAR value (current source address)

1 (B_0x1): at the end of a block transfer, the GPDMA_CxSAR register is updated by subtracting the programmed offset GPDMA_CxBR2.BRSAO from the current GPDMA_CxSAR value (current source address)

Block repeat destination address decrement Note: On top of this increment/decrement (depending on BRDDEC), GPDMA_CxDAR is in the same time also updated by the increment/decrement (depending on DDEC) of the GPDMA_CxTR3.DAO value, as it is usually done at the end of each programmed burst transfer.

0 (B_0x0): at the end of a block transfer, the GPDMA_CxDAR register is updated by adding the programmed offset GPDMA_CxBR2.BRDAO to the current GPDMA_CxDAR value (current destination address)

1 (B_0x1): at the end of a block transfer, the GPDMA_CxDAR register is updated by subtracting the programmed offset GPDMA_CxBR2.BRDAO from the current GPDMA_CxDAR value (current destination address)