Datasheet

345
32133D–11/2011
UC3D
Figure 20-8. Receiver Status
20.6.3.5 Parity
The USART supports five parity modes selected by MR.PAR. The PAR field also enables the
Multidrop mode, see ”Multidrop Mode” on page 346. If even parity is selected, the parity bit will
be a zero if there is an even number of ones in the data character, and if there is an odd number
it will be a one. For odd parity the reverse applies. If space or mark parity is chosen, the parity bit
will always be a zero or one, respectively. See Table 20-4.
The receiver will report parity errors in CSR.PARE, unless parity is disabled. Writing a one to
CR.RSTSTA will clear PARE. See Figure 20-9
Figure 20-9. Parity Error
D0 D1 D2 D3 D4 D5 D6 D7
RXD
Start
Bit
Parity
Bit
Stop
Bit
Baud Rate
Clock
Write
CR
RXRDY
OVRE
D0 D1 D2 D3 D4 D5 D6 D7
Start
Bit
Parity
Bit
Stop
Bit
RSTSTA = 1
Read
RHR
Table 20-4. Parity Bit Examples
Alphanum
Character Hex Bin
Parity Mode
Odd Even Mark Space None
A 0x41 0100 0001 1 0 1 0 -
V 0x56 0101 0110 1 0 1 0 -
R 0x52 0101 0010 0 1 1 0 -
D0 D1 D2 D3 D4 D5 D6 D7
RXD
Start
Bit
Bad
Parity
Bit
Stop
Bit
Baud Rate
Clock
Write
CR
PARE
RXRDY
RSTSTA = 1