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Section 10 Serial Communication Interface
Rev. 6.00 Sep 12, 2006 page 325 of 526
REJ09B0326-0600
When clock output mode is selected, SCI3 outputs 8 serial clock pulses. When an external clock is
selected, data is output in synchronization with the input clock.
Serial data is transmitted from the TXD pin in order from the LSB (bit 0) to the MSB (bit 7).
When the MSB (bit 7) is sent, checks bit TDRE. If bit TDRE is cleared to 0, SCI3 transfers data
from TDR to TSR, and starts transmission of the next frame. If bit TDRE is set to 1, SCI3 sets bit
TEND to 1 in SSR, and after sending the MSB (bit 7), retains the MSB state. If bit TEIE in SCR3
is set to 1 at this time, a TEI request is made.
After transmission ends, the SCK
3
pin is fixed at the high level.
Note: Transmission is not possible if an error flag (OER, FER, or PER) that indicates the data
reception status is set to 1. Check that these error flags (OER, FER, and PER) are all
cleared to 0 before a transmit operation.
Figure 10.17 shows an example of the operation when transmitting in synchronous mode.
Serial
clock
Serial
data
Bit 1
Bit 0
Bit 7
Bit 0
1 frame
1 frame
Bit 1
Bit 6
Bit 7
TDRE
TEND
LSI
operation
User
processing
TXI request
Data written
to TDR
TDRE cleared
to 0
TXI request
TEI request
Figure 10.17 Example of Operation when Transmitting in Synchronous Mode
Summary of Contents for F-ZTAT H8/3642A Series
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Page 124: ...Section 5 Power Down Modes Rev 6 00 Sep 12 2006 page 102 of 526 REJ09B0326 0600 ...
Page 188: ...Section 6 ROM Rev 6 00 Sep 12 2006 page 166 of 526 REJ09B0326 0600 ...
Page 190: ...Section 7 RAM Rev 6 00 Sep 12 2006 page 168 of 526 REJ09B0326 0600 ...
Page 298: ...Section 9 Timers Rev 6 00 Sep 12 2006 page 276 of 526 REJ09B0326 0600 ...
Page 378: ...Section 12 A D Converter Rev 6 00 Sep 12 2006 page 356 of 526 REJ09B0326 0600 ...
Page 446: ...Section 13 Electrical Characteristics Rev 6 00 Sep 12 2006 page 424 of 526 REJ09B0326 0600 ...