TSS461 ATMEL Corporation, TSS461 Datasheet - Page 49

• Manufacturer Part Number: TSS461
• Description: VAN Data Link Controller
• Manufacturer: ATMEL Corporation

Activate, Idle
and Sleep
Modes
Idle and Activate
Commands
Figure 30. Idle and Activate Timings
Sleep Command
4194C–AUTO–01/06
after reset
INT
RxD
TxD
RxD
Sleep, idle and activate commands are located in the Command Register (0x03). These three
commands are general commands for the TSS461E.
After reset, the TSS461E starts in idle mode. In this mode, the oscillator operates (CKOUT pin
active) but the circuit cannot transmit or receive anything on the VAN bus. The TxD output (pin
18) is in three-state mode, a pull-up resistor must be provided externally or by the line driver to
avoid floating state on the VAN bus.
To activate the TSS461E, the user must set the activate bit (ACTI) and reset the idle bit (IDLE).
In both cases, the idle state can be verified by reading the Line Status register (0x04).
If the user sets the sleep bit (SLEEP), the TSS461E enters in sleep mode, whatever are the val-
ues of activate and idle bits. All non-user registers are set-up to reduce the power consumption
and the internal oscillator is immediately stopped. However, all user registers (accessible by µP
bus) are always available by the user
To exit from this mode, the user must set either the idle bit or the activate bit.
In a typical application (Figure 12) using the CKOUT feature (pin 12), if the TSS461E is put in
sleep mode, the clock provided to the microcontroller is stopped. So, the system does not run
and the only way to awake this application is an external reset.
Idle mode
FCS
Idle command
(max)
3 TS
Activate mode
Activate command
8 TS
12 TS
4 TS
5 TS
Activate mode
SOF
SOF
TS: Timeslot period
Idle mode
TSS461E
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