Booting
15-28
ADSP-2126x SHARC Processor Hardware Reference
SPI word 9 = 0xBBSPI word 10 = 0xAA
SPI word 11 = 0x88SPI word 12 = 0x77
The initial boot of the 256-word loader kernel requires an 8-bit host to
transmit fifteen hundred thirty-six 8-bit words. The SPI DMA count
value of 0x180 is equal to 384 words. Since one 32-bit word is created
from four packed 8-bit words, the total number of 8-bit words transmitted
is 1536.
For all boot modes, the loader automatically outputs the correct
word width and count based on the project settings. For more
information, see the CrossCore or Vi+ tools
documentation.
Slave Boot Mode
In Slave boot mode, the host processor initiates the booting operation by
activating the
SPICLK
signal and asserting the
SPIDS
signal to the active
low state. The 256-word kernel is loaded 32 bits at a time, via the SPI
Receive Shift register (
RXSR
). To receive 256 instructions (48-bit words)
properly, the SPI DMA initially loads a DMA count of 0x180 (384)
32-bit words, which is equivalent to 0x100 (256) 48-bit words.
The processor’s
SPIDS
pin should not be tied low. When in SPI
Slave mode, including booting, the
SPIDS
signal is required to tran-
sition from high to low. SPI slave booting uses the default bit
settings shown in
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 ...