Renesas M32R/ECU Series User Manual page 508

12
ST : Start bit
b : Data bits
•
Clock-synchronous mode
•
7-bit UART mode
•
8-bit UART mode
•
9-bit UART mode
Note 1: Whether or not to add a parity bit is selectable.
Note 2: The stop bit can be chosen to be one bit or two bits long.
•
When transmitting
If the attribute (odd/even) represented by the
number of 1's in data bits agrees with the selected
parity attribute, a parity bit "0" is added. If the
attribute (odd/even) represented by the number of 1's
in data bits does not agree with the selected parity
attribute, a parity bit "1" is added.
LSB
ST b7 b6 b5 b4
Attribute derived from b7 + b6 + ... + b0
If it agrees with the selected
parity attribute, PAR = "0" is added.
If it does not agree with the selected
parity attribute, PAR = "1" is added.
Notes : • Shown above is an example of a data format in 8-bit UART mode.
• The data bit numbers (bn) above indicate bit numbers in a data list, and not the register bit numbers (bn).
Figure 12.2.7 Data Format When Parity is Enabled
PAR : Parity bit
SP : Stop bit
Direction of transfer
b7 b6
ST b6 b5
ST b7 b6
ST b8 b7
MSB
b3 b2 b1 b0
PAR SP
12.2 Serial I/O Related Registers
: One frame equivalent
b4 b3 b2 b1
b5
b3 b2 b1 b0
b4
b4 b3 b2 b1
b5
b5 b3
b4 b2
b6
•
When receiving
The received data is checked to see if the number of
1's included in its data and parity bits agrees with
the parity attribute (known as parity check).
LSB
ST b7 b6 b5
If the result of b7 + b6 + ... + b0 + PAR does not agree
with the selected parity attribute, a parity error is assumed
12-17
Serial I/O
b0
(Note 1) (Note 2)
PAR SP
(Note 2)
(Note 1)
b0 PAR SP
(Note 2)
(Note 1)
b1 b0 PAR SP
MSB
b4 b3 b2 b1 b0
PAR SP
32180 Group User's Manual (Rev.1.0)