Specific Blackfin Boot Modes
19-52
ADSP-BF537 Blackfin Processor Hardware Reference
shows the processing of a ZEROFILL block for this boot
mode. When the on-chip boot ROM encounters a ZEROFILL block, it
asserts the feedback strobe,
HWAIT
, to hold off the host from sending any
more bytes. During this time, it fills 0x4000 zeros to locations
0xFFA0 0300 – 0xFFA0 4300 via MDMA. When complete, the on-chip
boot ROM deasserts the feedback strobe and the host continues to send
the remaining bytes of the boot process (10-byte header for block 3 and
block 3 itself), as shown in
Figure 19-26. SPI Slave Mode Boot Sequence: Boot ZEROFILL Block
(Block 2 of DXE1)
1
1
SPICLK all
SPISS
all
MISO all
MOSI all
PFLAG all
0
0
ADDRESS
0xFFA00300
10-BYTE HEADER FOR BLOCK 2
OF DXE1 (ZERO-FILL BLOCK)
0
FLAG
0x01A3
FEEDBACK STROBE*
0
0
1
0
1
0
0
0
COUNT
0x00004000
* NOTE THAT THE NEXT BYTE OF DATA WILL BE SENT BY THE HOST. THE DATA WILL SIT IN THE FIFO UNTIL
THE FEEDBACK STROBE IS DEASSERTED. IN THIS CASE, IT IS THE FIRST BYTE (0x00) OF THE 10-BYTE HEADER
FOR BLOCK 3 OF DXE1.
**ASSERTION OF FEEDBACK STROBE (PFLAG) DURING ZERO-FILL BLOCK PROCESSING. PROCESSOR IS
ZERO-FILLING MEMORY VIA MemDMA DURING THIS TIME.
*
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...