HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 602

• Manufacturer Part Number: HD6417615
• Description: Hardware Manual
• Manufacturer: Hitachi Semiconductor

4. When modem control is enabled, transmission can be stopped and restarted in accordance with
Serial
data
TDFE
TEND
Serial
data
the CTS input value. When CTS is set to 1, if transmission is in progress, the line goes to the
mark state after transmission of one frame. When CTS is set to 0, the next transmit data is
output starting from the start bit.
Figure 14.7 shows an example of the operation when modem control is used.
CTS
TXI interrupt
request
1
Figure 14.6 Example of Transmit Operation in Asynchronous Mode
(Example with 8-Bit Data, Parity, One Stop Bit, LSB-First Transfer)
Figure 14.7 Example of Operation Using Modem Control (CTS)
Start
bit
0
Data written to SCFTDR
and TDFE flag cleared
to 0 by TXI interrupt handler
Start
bit
D0
0
D0
D1
One frame
D1
Data
D7
Drive high at this point
before stop bit
D7
Parity
bit
0/1
TXI interrupt
request
Parity
bit
0/1
Stop
bit
1
Stop
bit
Start
bit
0
D0
D1
Data
Start
bit
0
D7
D0
Parity
bit
0/1
D1
Stop
bit
1
Idle state
(mark state)
D7
0/1
1
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