Analog Devices ADSP-BF506F Hardware Reference Manual page 1118

Basic Booting Process
The boot kernel tests this field only on the first block and ignores the field
in further blocks (See
Table 24-3. Bus and DMA Width Coding
DMA Code DMA Width
0
reserved
1 8-bit
2 8-bit
3 8-bit
4 8-bit
5 8-bit
6 16-bit
7 16-bit
8 16-bit
9 16-bit
10 32-bit
11 32-bit
12 32-bit
13 64-bit
14 64-bit
15 128-bit
1 Reserved to differentiate from ADSP-BF53x boot streams.
2 Used by all byte-wise serial boot modes.
3 Applicable only to memory boot modes.
4 Not supported by ADSP-BF50x Blackfin products.
24-14
Table 24-3).
Source DMA
Modify
1
1
2
4
8
16
2
4
8
16
4
8
16
8
16
16
ADSP-BF50x Blackfin Processor Hardware Reference
Application
Default 8-bit boot from 8-bit source
Zero-padded 8-bit boot from 16-bit EBIU
Zero-padded 8-bit boot from 32-bit EBIU
Zero-padded 8-bit boot from 64-bit EBIU
Zero-padded 8-bit boot from 128-bit EBIU
Default 16-bit boot from 16-bit source
Zero-padded 16-bit boot from 32-bit EBIU
Zero-padded 16-bit boot from 64-bit EBIU
Zero-padded 16-bit boot from 128-bit EBIU
Default 32-bit boot from 32-bit source
Zero-padded 32-bit boot from 64-bit EBIU
Zero-padded 32-bit boot from 128-bit EBIU
Default 64-bit boot from 64-bit source
Zero-padded 64-bit boot from 128-bit EBIU
Default 128-bit boot from 128-bit source
2
3
4
4
3
4
4
3
4
4
4
4
4