GD32F10x User Manual
440
Figure 16-13. IrDA SIR ENDEC module
Normal
USART
Transmit
Encoder
Receive
Decoder
SIR MODULE
TX
RX
TX pin
RX pin
IREN
1
0
0
1
Infrared
LED
outside chip
inside chip
In IrDA mode, the polarity of the TX and RX pins is different. The TX pin is usually at low state,
while the RX pin is usually at high state. The IrDA pins keep stable to represent the logic ‘1’,
while an infrared light pulse on the IrDA pins (a Return to Zero signal) represents the logic ‘0’.
The pulse width should be 3/16 of a bit period. The IrDA could not detect any pulse if the pulse
width is less than 1 PSC clock. While it can detect a pulse by chance if the pulse width is
greater than 1 but smaller than 2 times PSC clock.
Because the IrDA is a half-duplex protocol, the transmission and the reception should not be
carried out at the same time in the IrDA SIR ENDEC block.
Figure 16-14. IrDA data modulation
Normal
tx frame
Stop
Start
1
0
0
0
0
0
0
1
1
1
1
Stop
Start
1
0
1
1
1
1
0
0
0
0
0
TX pin
Normal rx
frame
RX pin
The SIR submodule can work in low power mode by setting the IRLP bit in USART_CTL2.
The transmit encoder is driven by a low speed clock, which is divided from the PCLK. The
divide ratio is configured by the PSC[7:0] bits in USART_GP register. The pulse width on the
TX pin is 3 cycles of this low speed clock. The receiver decoder works in the same manner
as the normal IrDA mode.
Summary of Contents for GD32F10 Series
Page 63: ...GD32F10x User Manual 63 programmed during the chip production ...
Page 117: ...GD32F10x User Manual 117 010 1 0 011 0 9 ...
Page 416: ...GD32F10x User Manual 416 shadow register updates every update event ...
Page 427: ...GD32F10x User Manual 427 value ...
Page 518: ...GD32F10x User Manual 518 These bits are not used in SPI mode ...