Analog Devices ADSP-2181, Руководство пользователя

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Standard Operations
2-8 ADSP-2181 EZ-KIT Lite Evaluation System Manual
to the halt loop to wait for more characters. The only method of executing
your code once the halt loop has been entered is to send a
RUN
or
SINGLE
STEP
command in the debugger.
UART ISR
The UART Interrupt Service Routine (
Timer
ISR) is entered when your
code is running, but the host is still interacting with the board. As the host
sends bytes, the UART ISR takes the data stream from the UART and
builds the command. As with the halt loop, each character received is
passed to the command-processing kernel. Unlike the halt loop, the mon-
itor returns to your code immediately after the interrupt is serviced.
#
The following restrictions should be observed to ensure correct
board operation.
• The host loses contact with the monitor while the user program is
running if the user program disables the
Timer
interrupt or changes
the
Timer
interrupt vector.
• The host loses contact with the monitor while the program is run-
ning and it enters an Interrupt Service Routine when nesting is
turned on.
• The host cannot halt with the debugger’s Debug , Halt command if
global IRQ enable is disabled; however, breakpoints will work.
• The debugger will have trouble halting at a baud rate over 9600
while using the monitor program.
Command Processing
Command processing, initiated from either the UART ISR or the Halt
loop, is done in the command-processing kernel. This kernel parses the
commands and executes the instructions. If the instruction requires data
to be sent back to the host, the kernel initiates the response.