upd70f3017ay Renesas Electronics Corporation., upd70f3017ay Datasheet - Page 304

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

304
(iii) Transmission
The transmit operation is started when transmit data is written to transmit shift register n (TXSn). A start bit,
parity bit, and stop bit(s) are automatically added to the data.
Starting the transmit operation shifts out the data in TXSn, thereby emptying TXSn, after which a transmit
completion interrupt (INTSTn) is issued.
The timing of the transmit completion interrupt is shown below.
Caution Do not write to asynchronous serial interface mode register n (ASIMn) during a transmit
Remark
Figure 10-32. Timing of Asynchronous Serial Interface Transmit Completion Interrupt
TxDn (output)
TxDn (output)
INTSTn
INTSTn
operation. Writing to ASIMn during a transmit operation may disable further transmit
operations (in such cases, input RESET to restore normal operation).
Whether or not a transmit operation is in progress can be determined via software using
the transmit completion interrupt (INTSTn) or the interrupt request flag (STIFn) that is set
by INTSTn.
n = 0, 1
START
START
CHAPTER 10
D0
D0
User’s Manual U12768EJ4V1UD
SERIAL INTERFACE FUNCTION
D1
D1
(a) Stop bit length: 1
(b) Stop bit length: 2
D2
D2
D6
D6
D7
D7
Parity
Parity
STOP
STOP