ADSP-21368 SHARC Processor Hardware Reference 14-45
System Design
The following example shows a 48-bit instructions executed.
[0x90000] 0x112233445566
[0x90001] 0x7788AABBCCDD
The 16-bit SPI host packs or prearranges the data as:
The initial boot of the 256-word loader kernel requires a 16-bit host to
transmit 768 16-bit words. Two packed 16-bit words comprise the 32-bit
word. The SPI DMA count value of 0x180 is equivalent to 384 words.
Therefore, the total number of 16-bit words loaded is 768.
Figure 14-14. 16-Bit SPI Host Packing
SPI word 1 = 0x5566
SPI word 2 = 0x3344
SPI word 3 = 0x1122
SPI word 4 = 0xCCDD
SPI word 5 = 0xAABB
SPI word 6 = 0x7788
MOSI
16-bit
Word N
RXSPI
DMA
Internal
Memory
32 32
32
0x90000
0x900FF
16-bit
Word N
(Loader Kernel)
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