Infrared Data Transfer Mode - NEC mPD780024AS Series Preliminary User's Manual

13.4.3 Infrared data transfer mode

In infrared data transfer mode, the following data format pulse output and pulse receiving are enabled. The
relationship between the main system clock and baud rate is shown in Table 13-3.
(1) Data format
Figure 16-11 compares the data format used in UART mode with that used in infrared data transfer mode.
The IR (infrared) frame corresponds to the bit string of the UART frame, which consists of pulses – a start bit,
eight data bits, and a stop bit.
The length of the electrical pulses that are used to transmit and receive in an IR frame is 3/16 the length of the
cycle time for one bit (i.e., the "bit time"). This pulse (whose width is 3/16 the length of one bit time) rises from
the middle of the bit time (see the figure below).
Figure 13-11. Data Format Comparison Between Infrared Data Transfer Mode and UART Mode
0 1
Start bit D0
Start bit
0 1
Bit time
CHAPTER 13 SERIAL INTERFACE (UART0)
Bit time
Pulse width = 3/16 bit time
UART frame
Data bits
0 1 0
D1 D2 D3
IR frame
Data bits
0 1 0
Preliminary User's Manual U16035EJ1V0UM
0 1 1
D4 D5 D6
0 1 1
Pulse width =
3/16 bit time
0 1
D7 Stop bit
Stop bit
0 1
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