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

AXI Central Direct Memory Access LogiCORE IP Product Guide (PG034)
Document ID
PG034
Release Date
2022-05-18
Version
4.1 English

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

Figure 2-12:      BTT Register

X-Ref Target - Figure 2-12

pg034_btt_detail_x13291.jpg
Table 2-14:      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.(3)

Notes:

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 should only write to this register when the AXI CDMA is idle (CDMASR.IDLE = 1).