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What happens to early level of TxD pins?

Latest Updated:10/10/2006

Question:

When I select serial I/O mode of UARTi transmit/receive mode register (UiMR) in serial transmission, what happens to early level of TxD pins?

Answer:

After selecting clock synchronous serial I/O mode or UART mode in the serial I/O mode bit, the early level of TxD pins output "H" level till transmission start, but when NCH bit is "1" (N channel open drain output), TxD pins are in high impedance mode.
Suitable Products
R8C/18
R8C/19
R8C/1A
R8C/1B
R8C/20
R8C/21
R8C/22
R8C/23
R8C/24
R8C/25
R8C/26
R8C/27
R8C/28
R8C/29
R8C/2A
R8C/2B
R8C/2C
R8C/2D
R8C/2E
R8C/2F
R8C/2G
R8C/2H
R8C/2J
R8C/2K
R8C/2L
R8C/32C
R8C/33C
R8C/35C
R8C/36C
R8C/38C
R8C/3GC
R8C/3JC
R8C/32D
R8C/33D
R8C/35D
R8C/3GD
R8C/33T
R8C/38A
R8C/34E, R8C/34F, R8C/34G, R8C/34H
R8C/36E, R8C/36F, R8C/36G, R8C/36H
R8C/38E, R8C/38F, R8C/38G, R8C/38H