Texas Instruments SimpleLink CC2620 Technical Reference Manual page 1481

www.ti.com
23.3.2.4 Passing Data
There are two basic ways to pass data transmitted or received over the air: directly or through a queue.
The most straight-forward way to pass data is to append it as part of the command parameters (directly or
through a pointer). The exact format depends on the command being run; normally there is a length field
and a data buffer for TX and a maximum length, received length (if variable length), and receive buffer for
RX.
For some operations, the number of packets received or transmitted (or which packet out of a few that will
actually be transmitted) cannot be known in advance. For such operations, use a concept of queues. An
operation can use one or more queues, for instance one RX and one TX queue for a combined RX/TX
operation, or several queues depending on information in the received packets. Any operation using
queues uses a common system for maintaining them, as explained in
A radio operation command declares which data method is used.
23.3.2.5 Command Scheduling
The system CPU is responsible for scheduling the commands as required. When using low-power modes,
the system CPU must wake up a short time before the start of the next operation, using the RTC.
A radio operation command can be scheduled with a delayed start (see
is started with a delay, the radio CPU goes to idle mode until the command starts. The radio operation
command is considered to be running during this delay, and no other radio operation command can be
scheduled unless the pending command is aborted or stopped first.
The system CPU can schedule back-to-back radio operation commands by using the next operation
pointer in any radio operation command. This pointer can point to the next command to perform in the
chain, and by this method, complex operations can be made. Under some conditions (such as an error or
the expiration of a timer), the next command is not started. Instead, the operation ends or a number of
commands may be skipped (see
command is running, the system CPU must wait for the previous command or chain of commands to
finish. The IEEE 802.15.4 commands have exceptions for this rule.
When a radio operation command is finished, the radio CPU raises a COMMAND_DONE interrupt to the
system CPU. If a number of commands are chained as explained previously, the COMMAND_DONE
interrupt is raised after each command, while the LAST_COMMAND_DONE interrupt is raised after the
last command in the chain. For one, nonchained command, the LAST_COMMAND_DONE interrupt is also
raised after the command. When LAST_COMMAND_DONE is raised, COMMAND_DONE is always
raised at the same time. Before raising the COMMAND_DONE interrupt, the radio CPU updates the status
field of the command structure to a status that indicates that the command is finished. The radio CPU
does not access the command structure after raising the COMMAND_DONE interrupt.
SWCU117C – February 2015 – Revised September 2015
Submit Documentation Feedback
Section 23.3.2.5.2). If a new command is scheduled while another
Copyright © 2015, Texas Instruments Incorporated
RF Core HAL
Section 23.3.2.7.
Section 23.3.2.5.1). If a command
1481
Radio