BTT (CDMA Bytes to Transfer – Offset 28h) - 4.1 English - PG034

AXI Central Direct Memory Access LogiCORE IP Product Guide (PG034)
Document ID
PG034
Release Date
2025-07-11
Version
4.1 English

This register provides the value for the bytes to transfer for Simple DMA transfers by the AXI CDMA.

Figure 1. BTT Register
Table 1. BTT Register Details
Bits Field Name Default Value Access Type Description
31 to 26 Reserved 0 RO Writing to these bits has no effect, and they are always read as zeros.
25 to 0 BTT 0 R/W

Bytes to Transfer.

This register field is used for Simple DMA transfers and indicates the desired number of bytes to DMA from the Source Address to the Destination Address. A maximum of 67,108,863 bytes of data can be specified by this field for the associated transfer.

Writing to the BTT register also initiates the Simple DMA transfer.

  1. RO = Read Only. Writing has no effect.
  2. R/W = Read/Write
  3. A value of zero (0) is not allowed and causes a DMA internal error to be set by AXI CDMA. The software application must only write to this register when the AXI CDMA is idle (CDMASR.IDLE = 1).