UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 451

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

16.2.4 Parity Types and Operations
the transmission side and the reception side. With even parity and odd parity, 1 bit (odd number) errors can be detected.
With 0 parity and no parity, errors cannot be detected.
The parity bit is used to detect a bit error in the communication data. Normally, the same kind of parity bit is used on
• Even parity
• Odd parity
• 0 parity
• No parity
If the number of bits with a value of “1” in the transmit data is odd, the parity bit is set to “1”, and if the number of
“1” bits is even, the parity bit is set to “0”. Control is thus performed to make the number of “1” bits in the transmit
data plus the parity bit an even number. In reception, the number of “1” bits in the receive data plus the parity bit is
counted, and if this number is odd, a parity error is generated.
Conversely to the case of even parity, control is performed to make the number of “1“ bits in the transmit data plus
the parity bit an odd number.
In reception, a parity error is generated if the number of “1” bits in the receive data plus the parity bit is even.
In transmission, the parity bit is set to “0” irrespective of the receive data.
In reception, parity bit detection is not performed. Therefore, no parity error is generated irrespective of whether the
parity bit is “0” or “1”.
In transmission, a parity bit is not added.
In reception, reception is performed on the assumption that there is no parity bit. Since there is no parity bit, no parity
error is generated.
CHAPTER 16 ASYNCHRONOUS SERIAL INTERFACE/3-WIRE SERIAL I/O
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