TJA1080A All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
Product data sheet Rev. 6 — 28 November 2012 18 of 49
NXP Semiconductors
TJA1080A
FlexRay transceiver
6.3.2 Star-transmit mode
This mode is entered if one of the following events occur:
• If the transceiver is in Star-idle mode and activity is detected on pin TXEN.
• If the transceiver is in Star-idle mode and activity is detected on pins TRXD0 and
TRXD1.
In Star-transmit mode the transmitter is enabled and the transceiver can transmit data on
the bus lines and on the TRXD lines. It transmits the data received on pins TXD or TRXD0
and TRXD1, depending on where activity is detected:
• If activity is detected on the TRXD lines, the transceiver transmits data from pins
TRXD0 and TRXD1 to the bus.
• If activity is detected on the TXEN, the transceiver transmits data from pin TXD to the
bus and to the TRXD lines.
6.3.3 Star-receive mode
This mode is entered if the transceiver is in Star-idle mode and activity has been detected
on the bus lines.
In Star-receive mode the transceiver transmits data received on the bus via the TRXD0
and TRXD1 lines to other transceivers connected to the TRXD lines. The transmitter is
always disabled. RXD, which represents the data on the bus lines, is output at TRXD0 and
TRXD1.
6.3.4 Star-standby mode
This mode is entered if one of the following events occur:
• From Star-idle, Star-transmit or Star-receive modes if the wake flag is set and an
undervoltage on pin V
CC
is present for longer than t
to(uv)(VCC)
.
• If the PWON flag is set.
In Star-standby mode the transceiver has entered a low power mode. In this mode the
current consumption is as low as possible to prevent discharging the capacitor at pin
V
BUF
.
If pins V
IO
and V
BUF
are within their operating range, pins RXD and RXEN will indicate the
wake flag.
