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3 pins of uart, Pins of uart – FUJITSU F2MC-8L F202RA User Manual

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CHAPTER 13 UART

13.3

Pins of UART

Pins relating to UART are the clock I/O pin (P30/UCK/SCK), serial data output pin
(P31/UO/SO), and serial data input pin (P32/UI/SI).

UART Relating Pins

P30/UCK/SCK

This pin functions as the general-purpose I/O port (P30), UART clock I/O pin (UCK), or 8-bit serial clock

I/O pin (SCK). When clock output is enabled (SMC: SCKE = 1), this pin functions as the UART clock

output pin (UCK) regardless of the value in the corresponding port direction register. When this pin

functions as the UART clock, do not use any external clock (SRC: CS1 and CS0 must be other than 00

B

).

When using this pin as the UART clock input pin, disable clock output (SMC: SCKE = 0) and set it as the

input port using the corresponding port direction register (DDR3: bit0 = 0). In this case, be sure to select

the external clock (SRC: CS1 and CS0 = 00

B

).

P31/UO/SO

This port functions as the general-purpose I/O port (P31), UART serial data output pin (UO), or 8-bit serial

data output pin (SO). When serial data output is enabled (SMC: SOE = 1), this pin functions as the UART

serial data output pin (UO) regardless of the value in the corresponding port direction register.

P32/UI/SI

This port functions as the general-purpose I/O port (P32), UART serial data input pin (UI), or 8-bit serial

data input pin (SI). When using this pin as the UART serial data input pin, set this pin as the input port by

using the corresponding port direction register (DDR3: bit2 = 0).

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