RM0312 datasheet(245/275 Pages) STMICROELECTRONICS

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RM0312

Universal synchronous/asynchronous receiver transmitter (USART)

249

21.6.3

Baud rate register 1 (USART_BRR1)

The baud rate registers are common to both the transmitter and the receiver. The baud rate

is programmed using two registers BRR1 and BRR2. Writing of BRR2 (if required) should

precede BRR1, since a write to BRR1 will update the baud counters.

See Figure 87: How to code USART_DIV in the BRR registers on page 235 and Table 46:

Baud rate programming and error calculation on page 236.

Note:

The baud counters stop counting if the TEN or REN bits are disabled respectively.

Address offset: 0x02

Reset value: 0x00

21.6.4

Baud rate register 2 (USART_BRR2)

Address offset: 0x03

Reset value: 0x00

654

3210

USART_DIV[11:4]

Bits 7:0 USART_DIV[11:4]: USART_DIV bits (1)

These 8 bits define the 2nd and 3rd nibbles of the 16-bit USART divider (USART_DIV).

1. BRR1 = 0x00 means USART clock is disabled.

654

3210

USART_DIV[15:12]

USART_DIV[3:0]

Bits 7:4 USART_DIV[15:12]: MSB of USART_DIV

These 4 bits define the MSB of the USART Divider (USART_DIV)

Bits 3:0 USART_DIV[3:0]: LSB of USART_DIV

These 4 bits define the LSB of the USART Divider (USART_DIV)

RM0312 Datasheet(PDF) 245 Page - STMicroelectronics