TJA1086G All information provided in this document is subject to legal disclaimers. © NXP B.V. 2017. All rights reserved.
Product data sheet Rev. 1 — 13 July 2017 17 of 64
NXP Semiconductors
TJA1086G
FlexRay active star coupler)
7.9 Branch operating modes
Each of the two branches in the TJA1086G features six branch operating modes:
• Branch_Off
Both branches are in Branch_Off mode when the TJA1086G is in AS_PowerOff or
AS_Reset mode. The transmitter, normal receiver, low-power receiver and bus error
detection are disabled. The bus pins are floating.
• Branch_LowPower
Both branches are in Branch_LowPower mode when the TJA1086G is in AS_Standby
or AS_Sleep mode. The transmitter, the normal receiver and bus error detection are
disabled. The low-power receiver is active (i.e. remote wake-up is possible). The bus
pins are biased to ground.
• Branch_Disabled
The TJA1086G switches to Branch_Disabled if an overtemperature is detected. The
‘Branch_Disabled’ and ‘Branch_Normal’ commands allow the host to enable/disable a
branch without affecting the other branch. The transmitter, normal receiver and bus
error detection are disabled. Only the low-power receiver is active (remote wake-up is
possible). The bus pins are biased to V
o(idle)(BP)
and V
o(idle)(BM)
.
• Branch_Normal
When a branch is in Branch_Normal, the TJA1086G will be in AS_Normal. The
transmitter, normal receiver and bus error detection are active. The bus pins are
biased to V
o(idle)(BP)
and V
o(idle)(BM)
.
• Branch_TxOnly1
In Branch_TxOnly1 mode, the receiver is disabled, i.e. the received data is not
forwarded to the signal router. The transmitter is active and bus error detection is
active. The bus pins are biased to V
o(idle)(BP)
and V
o(idle)(BM)
.
• Branch_TxOnly2
This mode is host-controlled only and is operationally identical to Branch_TxOnly1. It
allows the host to switch off the receiver in response to error conditions.
• Branch_FailSilent
The transmitter, the low-power receiver and bus error detection are disabled. Only the
receiver remains active to monitor the branch for idle or activity. Received data is not
forwarded to the signal router. The bus pins are biased to V
o(idle)(BP)
and V
o(idle)(BM)
.
7.9.1 Branch operating mode transitions
Branch-related host commands can only be issued when the TJA1086G is in AS_Normal
mode.
7.9.1.1 Branch_Off
When the TJA1086G enters AS_PowerOff or AS_Reset, both branches switch to
Branch-Off. When the TJA1086G subsequently switches to AS_Standby, both branches
switch to Branch_LowPower.
7.9.1.2 Branch_LowPower
Both branches switch to Branch_LowPower when the TJA1086G enters AS_Standby or
AS_Sleep. Both branches will remain in this mode until the TJA1086G enters AS_Normal.
When this transition happens, any branch that was in Branch_Disabled before switching
to Branch_LowPower will return to Branch_Disabled. Otherwise, both branches switch to
