Datasheet

78K0/Ix2 CHAPTER 14 SERIAL INTERFACE UART6/DALI
R01UH0010EJ0500 Rev.5.00 461
Feb 28, 2012
 Backward frame
This is a frame used when transmitting from the slave to a master. A frame consists of 11 bits.
Figure 14-28. Backward-Frame Structure
a b c
1-bit 8-bit 2-bit
a: Start bit
This indicates the start of the frame. It is always the same waveform as “1”.
b: Data byte
This replies to the master.
c: Stop bit
This indicates the end of the frame. It is fixed to the high level.
(2) Transmission/reception timing rules
<1> Timing in the frame
The DALI bit width is one bit (= 833.3
 s 10%) for both Forward and Backward frames.
Figure 14-29. Timing in the Frame
Data bit
833.3 μs
Data bit
833.3 μs
Data bit
833.3 μs
Stop bit
Note
1666.67 μs
Start bit
833.3 μs
Note The stop bit width is 1666.67
 s for 2 stop bits.
<2> Timing among frames
With DALI, the following timing must be controlled in frame units.
 Forward frame width: 15.83 ms 10%
 Backward frame width: 9.17 ms 10%
 Communication interval between one Forward frame and the Backward frame: 2.92 to 9.17 ms
 Communication interval between one Forward frame and the next Forward frame: 9.17 ms min.
 Communication interval between one Backward frame and the next Forward frame: 9.17 ms min.
Figure 14-30. Timing among frames
15.83 ms 9.17 ms
Forward start - Backward start
9.17 ms
min.
9.17 ms
min.
2.92 to
9.17 ms
Forward
frame
Forward
frame
Forward
frame
Backward
frame