NXP Semiconductors PXN2020 - 26.6.14 Key Slot Transmission; 26.6.14.1 Key Slot Assignment; 26.6.14.2 Key Slot Transmission in POC:startup; 26.6.14.3 Key Slot Transmission in POC:normal active

FlexRay Communication Controller (FlexRAY)
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor 26-139
Eqn. 26-19
Eqn. 26-20
Eqn. 26-21
The MTS is transmitted over channel B in the communication cycle with number CYCCNT, if
Equation 26-19, Equation 26-22, and Equation 26-23 are fulfilled.
Eqn. 26-22
Eqn. 26-23
26.6.14 Key Slot Transmission
26.6.14.1 Key Slot Assignment
A key slot is assigned to the controller if the key_slot_id field in the Protocol Configuration Register 18
(PCR18) is configured with a value greater than 0 and less or equal to number_of_static_slots in Protocol
Configuration Register 2 (PCR2), otherwise no key slot is assigned.
26.6.14.2 Key Slot Transmission in POC:startup
If a key slot is assigned and the controller is in the POC:startup state, startup null frames will be
transmitted as specified by FlexRay Communications System Protocol Specification, Version 2.1 Rev A.
26.6.14.3 Key Slot Transmission in POC:normal active
If a key slot is assigned and the controller is in POC:normal active, a frame of the type as shown in
Table 26-115 is transmitted. If a transmit message buffer is configured for the key slot and a valid message
is available, a message frame is transmitted (see Section 26.6.6.2.5, Message Transmission). If no transmit
message buffer is configured for the key slot or no valid message is available, a null frame is transmitted
(see Section 26.6.6.2.6, Null Frame Transmission).
26.6.15 Sync Frame Filtering
Each received synchronization frame must pass the Sync Frame Acceptance Filter and the Sync Frame
Rejection Filter before it is considered for clock synchronization. If the synchronization frame filtering is
Table 26-115. Key Slot Frame Type
PCR11[key_slot_used_for_sync] PCR11[key_slot_used_for_startup] key slot frame type
0 0 normal frame
0 1 normal frame
1
1
The frame transmitted has an semantically incorrect header and will be detected as an invalid frame at the receiver.
1 0 sync frame
1 1 startup frame
PSR0 PROTSTATEPOC:normal active=
MTSACRF MTE1=
CYCCNT & MTSACFR CYCCNTMSKMTSACFR CYCCNTVAL & MTSACFR CYCCNTMSK=
MTSBCRF MTE1=
YCCNT & MTSBCFR CYCCNTMSKMTSBCFR CYCCNTVAL & MTSBCFR CYCCNTMSK=