PXS20RM Datasheet, PDF (892/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

FlexRay Communication Controller
26.7.6 Protocol Control Command Execution
This section considers the issues of the protocol control command execution.
The application issues any of the protocol control commands listed in the POCCMD field of Table 26-16
by writing the command to the POCCMD field of the Protocol Operation Control Register (FR_POCR).
As a result the CC sets the BSY bit while the command is transferred to the PE. When the PE has accepted
the command, the BSY flag is cleared. All commands are accepted by the PE.
The PE maintains a protocol command vector. For each command that was accepted by the PE, the PE sets
the corresponding command bit in the protocol command vector. If a command is issued while the
corresponding command bit is set, the command is not queued and is lost.
If the command execution block of the PE is idle, it selects the next accepted protocol command with the
highest priority from the current protocol command vector according to the protocol control command
priorities given in Table 26-136. If the current protocol state does not allow the execution of this protocol
command (see POC state changes in FlexRay Communications System Protocol Specification, Version 2.1
Rev A) the CC asserts the illegal protocol command interrupt flag IPC_IF in the Protocol Interrupt Flag
Register 1 (FR_PIFR1). The protocol command is not executed in this case.
Some protocol commands may be interrupted by other commands or the detection of a fatal protocol error
as indicated by Table 26-136. If the application issues the FREEZE or READY command, or if the PE
detects a fatal protocol error, some commands already stored in the command vector will be removed from
this vector.
Table 26-136. Protocol Control Command Priorities
Protocol Command
FREEZE
READY
CONFIG_COMPLETE
ALL_SLOTS
ALLOW_COLDSTART
RUN
WAKEUP
DEFAULT_CONFIG
CONFIG
HALT
Priority
Interrupted By
Cleared and Terminated By
(highest) 1
2 _none
3
4
FREEZE, READY, CONFIG_COMPLETE,
fatal protocol error
5
6
FREEZE,
FREEZE,
READY,
fatal protocol error
CONFIG_COMPLET,
7 _{fatal protocol error} FREEZE,
fatal protocol error
8
FREEZE,
fatal protocol error
9
(lowest) 10
FREEZE, READY, CONFIG_COMPLETE,
fatal protocol error
26-180
PXS20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor