NEC Renesas V850/SC1 User Manual page 451

(b) Parity types and operations
The parity bit is used to detect bit errors in transfer data. Usually, the same type of parity bit is used by the
transmitting and receiving sides. When odd parity or even parity is set, errors in the parity bit (the odd-
number bit) can be detected. When zero parity or no parity is set, errors are not detected.
(i) Even parity
•
During transmission
The number of bits in transmit data including a parity bit is controlled so that the number of "1" bits
is even. The value of the parity bit is as follows.
If the transmit data contains an odd number of "1" bits:
If the transmit data contains an even number of "1" bits:
•
During reception
The number of "1" bits among the receive data is counted, including a parity bit, and a parity error
is generated when the result is an odd number.
(ii) Odd parity
•
During transmission
The number of bits in transmit data including a parity bit is controlled so that the number of "1" bits
is odd. The value of the parity bit is as follows.
If the transmit data contains an odd number of "1" bits:
If the transmit data contains an even number of "1" bits:
•
During reception
The number of "1" bits among the receive data is counted, including a parity bit, and a parity error
is generated when the result is an even number.
(iii) Zero parity
During transmission, the parity bit is set to "0" regardless of the transmit data.
During reception, the parity bit is not checked. Therefore, no parity errors will be generated regardless
of whether the parity bit is a "0" or a "1".
(iv) No parity
No parity bit is added to the transmit data.
During reception, receive data is regarded as having no parity bit. Since there is no parity bit, no parity
errors will be generated.
CHAPTER 11 SERIAL INTERFACE FUNCTION
User's Manual U15109EJ3V0UD
The parity bit value is "1"
The parity bit value is "0"
The parity bit value is "0"
The parity bit value is "1"
449