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M451
May. 4, 2018
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6.13.4 Basic Configuration
The UART Controller function pins are configured in SYS_GPA_MFPL, SYS_GPA_MFPH,
SYS_GPB_MFPL, SYS_GPB_MFPH, SYS_GPC_MFPL, SYS_GPD_MFPL, SYS_GPD_MFPH
and SYS_GPE_MFPH Multiple Function Registers.
The UART Controller clock are enabled in UAR0TCKEN (CLK_APBCLK0[16]) for UART0,
UART1CKEN(CLK_APBCLK0[17]) for UART1, UART2CKEN(CLK_APBCLK0[18] for UART2 and
UART3CKEN(CLK_APBCLK0[19] for UART3.
The UART Controller clock source is selected by UARTSEL (CLK_CLKSEL1[25:24]).
The UART Controller clock pre-scale is determined by UARTDIV (CLK_CLKDIV0[11:8]).
UART Interface Controller Pin description is shown as Table 6-22:
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 6-22 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 UART_FUNCSEL register. The four function modes will
be described in following section.
UART Controller Baud Rate Generator
6.13.5.1
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 Table 6-23 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. More detail
register description is shown in UART_BAUD register. There are three setting mode. Mode 0 is
set by UART_BAUD[29:28] with 00. Mode 1 is set by UART_BAUD[29:28] with 10. Mode 2 is set
by UART_BAUD[29:28] with 11.
Mode
BAUDM1
BAUDM0
Baud Rate Equation
Mode 0
0
0
UART_CLK / [16 * (BRD+2)]
Mode 1
1
0
UART_CLK / [(1) * (BRD+2)], EDIVM1 must >= 8
Mode 2
1
1
UART_CLK / (BRD+2)
.If UART_CLK <= 3*HCLK, BRD must >= 9.
If UART_CLK > 3*HCLK, BRD must >= 3*N
– 1.
N is the smallest integer larger than or equal to the ratio of UART_CLK /HCLK.
For example,
if 3*HCLK < UART_CLK =< 4*HCLK, BRD must >=11.
if 4*HCLK < UART_CLK =< 5*HCLK, BRD must >=14.
Table 6-23 UART Controller Baud Rate Equation Table
Содержание ARM Cortex NuMicro M451 Series
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Страница 324: ...M451 May 4 2018 Page 324 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL Figure 6 4 18 Checksum Calculation Flow...
Страница 355: ...M451 May 4 2018 Page 355 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL 2 0 Reserved Reserved...
Страница 625: ...M451 May 4 2018 Page 625 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL 00 5 bits 01 6 bits 10 7 bits 11 8 bits...
Страница 721: ...M451 May 4 2018 Page 721 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL the SCL line 1 0 Reserved Reserved...
Страница 1001: ...M451 May 4 2018 Page 1001 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL LQFP 64L 10x10x1 4 mm footprint 2 0 mm 9 2...
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Страница 1003: ...M451 May 4 2018 Page 1003 of 1006 Rev 2 08 M451 SERIES TECHNICAL REFERENCE MANUAL LQFP 48L 7x7x1 4mm footprint 2 0mm 9 4...