upd70f3017ay Renesas Electronics Corporation., upd70f3017ay Datasheet - Page 302

• Manufacturer Part Number: upd70f3017ay
• Description: V850/sa1tm 32-/16-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

(c) Communication operations
302
(i) Data format
As shown in Figure 10-31, the format of the transmit/receive data consists of a start bit, character bits, a parity
bit, and one or more stop bits.
Asynchronous serial interface mode register n (ASIMn) is used to set the character bit length, parity selection,
and stop bit length within each data frame (n = 0, 1).
• Start bit ............. 1 bit
• Character bits ... 7 bits or 8 bits
• Parity bit ...........
• Stop bit(s) ........
When 7 bits is selected as the number of character bits, only the lower 7 bits (from bit 0 to bit 6) are valid, so
that during a transmission the highest bit (bit 7) is ignored and during reception the highest bit (bit 7) must be
set to 0.
Asynchronous serial interface mode register n (ASIMn) and baud rate generator control register n (BRGCn)
are used to set the serial transfer rate (n = 0, 1).
If a receive error occurs, information about the receive error can be ascertained by reading asynchronous
serial interface status register n (ASISn) (n = 0, 1).
Figure 10-31. Format of Transmit/Receive Data in Asynchronous Serial Interface
Start
bit
D0
Even parity, odd parity, zero parity, or no parity
1 bit or 2 bits
CHAPTER 10
D1
D2
User’s Manual U12768EJ4V1UD
D3
SERIAL INTERFACE FUNCTION
1 data frame
D4
D5
D6
D7
Parity
bit
Stop bit