NuMicro® NUC029LEE/NUC029SEE
32-bit Arm
®
Cortex
®
-M0 Microcontroller
Aug, 2018
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Rev 1.00
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UC029
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CHN
ICA
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Pin
Type
Description
UART_TXD
Output
UART transmit
UART_RXD
Input
UART receive
UART_nCTS
Input
UART modem clear to send
UART_nRTS
Output
UART modem request to send
Table 6.13-1 UART Interface Controller Pin
6.13.5 Functional Description
The UART Controller supports four function modes including UART, IrDA, LIN and RS-485 mode.
User can select a function by setting the UA_FUN_SEL register. The four function modes will be
described in following section.
6.13.5.1 UART Controller Baud Rate Generator
The UART Controller includes a programmable baud rate generator capable of dividing clock
input by divisors to produce the serial clock that transmitter and receiver need. The baud rate
equation is Baud Rate = UART_CLK / M * [BRD + 2], where M and BRD are defined in Baud
Rate Divider Register (UA_BAUD). The following tables list the UART baud rate equations in the
various conditions and UART baud rate parameter settings. There is no error for the baud rate
results calculated through the baud rate parameter and register setting below. In IrDA function
mode, the baud rate generator must be set in Mode 0.
Mode
DIV_X_EN
DIV_X_ONE
Divider X
BRD
Baud Rate Equation
0
0
0
Don’t care
A
UART_CLK / [16 * (A+2)].
1
1
0
B
A
UART_CLK / [(B+1) * (A+2)] , B must >= 8.
2
1
1
Don’t care
A
UART_CLK / (A+2),
If UART peripheral clock<= HCLK, A must >=9.
If HCLK <UART peripheral clock <= 2*HCLK, A must
>=15.
If 2*HCLK <UART peripheral clock <= 3*HCLK, A
must >=21.
If UART peripheral clock > 3*HCLK, it is unsupported.
UART peripheral clock = UART clock source/(UART
clock divider 1).
Table 6.13-2 UART Baud Rate Equation
UART Peripheral Clock = 22.1184 MHz
Baud Rate
Mode 0
Mode 1
Mode 2
921600
Not support
A=0, B=11
A=22
460800
A=1
A=1, B=15
A=46