Texas Instruments TMS320C3 Series, User Manual, Page: 43 / 166

DSK Communications Kernel
4-9 Functional Overview
Commands
When the ’C31 receives an interrupt from the host (INT2), the ’C31 saves the
current state of the CPU and then receives a packet. Once the ’C31 receives
the packet, the communications kernel analyzes the command entry in the
header to direct the handling of the packet. The command entry provides the
low-level routines necessary to communicate with the host and debug the sys-
tem. The communications kernel supports these commands:
XWRIT Write a block of data from the host to the DSK. This command
takes data-stream-length items from the host and writes them
into the ’C31’s memory location pointed to by the target address.
The target address is incremented by the target index after each
write operation.
XREAD Read a block of data from the DSK to the host. This command
reads data-stream-length items from the ’C31’s memory location
pointed at by the target address
and sends them to the host. The
target index increments the target address
after each read opera-
tion.
XCTXT Get the ’C31 context save buffer address.
XRUNF Restore the context of the CPU and execute code until a break-
point is encountered or a halt command is issued. This command
is used for debugging.
XSTEP Restore the context of the CPU, execute a single instruction, and
then save the context of the CPU. This command is used for de-
bugging.
XHALT Save the context of the CPU and wait for a new command. This
command is used for debugging.