Posted on May 17, 2011 at 12:18Hi,
For a specific application I want to use the USART in 9 databits mode in combination with 2 stopbits.
The reference manual description of Control register 1 (USART_CR1) states that this combination is not possible:
''Bit 12 M: word length.
This bit determines the word length. It is set or cleared by software.
0: 1 Start bit, 8 Data bits, n Stop bit
1: 1 Start bit, 9 Data bits, 1 Stop bit''In smartcard mode however, a setting is described with M=1 in combination with 1.5 stopbits:
''8 bits plus parity: where M=1 and PCE=1 in the USART_CR1 register and either:
– 0.5 stop bits when receiving: where STOP=’01’ in the USART_CR2 register
– 1.5 stop bits when transmitting: where STOP=’11’ in the USART_CR2 register.''Question:
Is the number of stopbits in 9 bit datamode indeed limited to one?
Thanks in advance for your answer!
Hans Rosenbrand
