NEC 78K0S/KB1+ User Manual page 201

(c) Normal transmission
When bit 7 (POWER6) of asynchronous serial interface operation mode register 6 (ASIM6) is set to 1, and
<R>
then bit 6 (TXE6) of ASIM6 is set to 1 after one clock of the base clock (f
enable status is entered. Transmission can be started by writing transmit data to transmit buffer register 6
(TXB6). The start bit, parity bit, and stop bit are automatically appended to the data.
When transmission is started, the data in TXB6 is transferred to transmit shift register 6 (TXS6). After that,
the data is sequentially output from TXS6 to the T
stop bits set by ASIM6 are appended and a transmission completion interrupt request (INTST6) is generated.
Transmission is stopped until the data to be transmitted next is written to TXB6.
Figure 11-15 shows the timing of the transmission completion interrupt request (INTST6). This interrupt
occurs as soon as the last stop bit has been output.
1. Stop bit length: 1
T D6 (output)
X
2. Stop bit length: 2
T D6 (output)
X
CHAPTER 11 SERIAL INTERFACE UART6
Figure 11-15. Normal Transmission Completion Interrupt Request Timing
Start D0
INTST6
Start D0
INTST6
D6 pin. When transmission is completed, the parity and
X
D1 D2 D6
D1 D2 D6
User's Manual U17446EJ3V1UD
) has elapsed, transmission
XCLK6
Parity
D7 Stop
D7 Parity Stop
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