Maxim Integrated MAX32600, Руководство пользователя

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MAX32600 User’s Guide Communication Peripherals 7.3 UART
The formulas for calculating the UARTn_BAUD_INT and UARTn_BAUD_DIV_128 are:
div
=
System Core Clock
(
DESIRED BAUD RATE
100
∗
128 )
• UARTn_BAUD_INT is equal to the integer portion of div.
UART n
_
BAU D
_
INT =
div
100
• UARTn_BAUD_DIV_128 is the decimal portion of div converted to an integer.
UART n _ BAU D _ DIV _ 128 =
((
div
−
UART n _ BAU D _ INT
) ∗
100
) ∗
128
100
Note The PLL output must be selected as the system clock source for proper UART operation. Using the crypto ring or the nano ring as the clock source
will not provide sufficient clock accuracy to generate a stable baud rate.
The number of stop bits used and parity calculation mode are all set by writing to the appropriate bits and bit fields in the UARTn_CTRL register.
• UARTn_CTRL.parity_enable is used to enable parity.
• UARTn_CTRL.parity_mode is used to set even or odd parity.
• UARTn_CTRL.parity_bias is used to determine if 0s or 1s are used for parity determination.
• UARTn_CTRL.stop_bit_mode is used to set the number of stop bits.
To set the transfer size (character length), the UARTn_CTRL.char_length field must be set.
UART Character Size (2b) Setting
00b 5-bit character
01b 6-bit character
01b 7-bit character
11b 8-bit character
Rev.1.3 April 2015 Maxim Integrated Page 287