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DSK Communications Kernel
4-8
4.2 DSK Communications Kernel
Upon reset, the host downloads a communications kernel to the ’C31 using the
bootloader. This communications kernel provides a set of low-level routines
that allow the host and the ’C31 to exchange information and perform debug-
ging functions.
Data packets
The host and the ’C31 communicate by exchanging packets of data.
Figure 4–5 shows the structure for data packets. The data-packet headers
(shaded section) typically consist of four fields:
command, data-stream length,
target address, and target index. This header is followed by the data stream
as shown in Figure 4–5. The header fields are described as follows:
-
Command directs the handling of the packets. See the Commands sec-
tion, page 4-9, for more information.
-
Data-stream length indicates the length of data in the data stream.
-
Target address points to the memory location where data is read from or
written to.
-
Target index post-increments the value of the target address after a read
or write of a single data item.
Figure 4–5. Data-Packet Structure
Command
Data-stream length
Target address
Target index
ÁÁÁÁÁÁÁÁÁÁ
Á ÁÁÁÁÁÁÁÁ Á
Á ÁÁÁÁÁÁÁÁ Á
ÁÁÁÁÁÁÁÁÁÁ
Data stream