CHAPTER 12 SERIAL INTERFACE UART6
Preliminary User’s Manual U16846EJ1V0UD
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(c) Normal transmission
The T
X
D6 pin outputs a high level when bit 7 (POWER6) of asynchronous serial interface operation mode
register 6 (ASIM6) is set to 1. If bit 6 (TXE6) of ASIM6 is then set to 1, transmission is enabled.
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
X
D6 pin. When transmission is completed, the parity bit
and stop bit set by ASIM6 are added and a transmission completion interrupt request (INTST6) is generated.
Transmission is stopped until the data to be transmitted next is written to TXB6.
Figure 12-15 shows the timing of the transmission completion interrupt request (INTST6). This interrupt
occurs as soon as the last stop bit has been output.
Figure 12-15. Normal Transmission Completion Interrupt Request Timing
1. Stop bit length: 1
INTST6
D0
Start
D1
D2
D6
D7
Stop
T
X
D6 (output)
Parity
2. Stop bit length: 2
T
X
D6 (output)
INTST6
D0
Start
D1
D2
D6
D7
Parity
Stop