
ADSP-2126x SHARC Processor Hardware Reference
15-31
System Design
The SPI DMA channel is used when downloading the boot kernel infor-
mation to the processor. At reset, the DMA parameter registers are
initialized to the values listed in
From the perspective of the ADSP-2126x processor, there is no difference
between booting from the three types of SPI slave devices. Since SPI is a
full-duplex protocol, the processor is receiving the same amount of bits
that it sends as a read command. The read command comprises a full
32-bit word (which is what the processor is initialized to send) comprised
of a 24-bit address with an 8-bit opcode. The 32-bit word that is received
while this read command is transmitted is thrown away in hardware, and
can never be recovered by the user. Because of this, special measures must
be taken to guarantee that the boot stream is identical in all three cases.
The processor boots in Least Significant Bit First (LSBF) format, while
most serial memory devices operate in Most Significant Bit First (MSBF)
format. Therefore, it is necessary to program the device in a fashion that is
compatible with the required LSBF format.
Also, because the processor always transmits 32 bits before it begins read-
ing boot data from the slave device, it is necessary for the CrossCore or
Vi+ tools to insert extra data to the boot image (in the loader
file) if using memory devices that do not use the LSBF format. CrossCore
Table 15-12. Parameter Initialization Value for Master Boot
Parameter Register
Initialization Value
Comment
SPICTL
0x0000 5D06
SPIBAUD
0x0064
CCLK/400 =500 KHz@ 200 MHz
SPIFLG
0xfe01
FLG0 used as slave-select
SPIDMAC
0x0000 0007
Enable receive interrupt on completion
IISPI
0x0008 0000
Start of block 0 normal word memory
IMSPI
0x0000 0001
32-bit data transfers
CSPI
0x0000 0180
0x100 instructions = 0x180 32-bit words
Summary of Contents for ADSP-21261 SHARC
Page 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Page 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Page 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Page 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Page 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Page 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Page 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Page 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Page 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Page 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Page 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Page 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...