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Section 10 Serial Communication Interface
Rev. 6.00 Sep 12, 2006 page 283 of 526
REJ09B0326-0600
Bit 0
Start Flag (STF):
Bit 0 controls the start of a transfer. Setting this bit to 1 causes SCI1 to
start transferring data.
During the transfer or while waiting for the first clock pulse, this bit remains set to 1. It is cleared
to 0 upon completion of the transfer. It can therefore be used as a busy flag.
Bit 0: STF
Description
0
Read: Indicates that transfer is stopped
(initial value)
Write:
Invalid
1
Read: Indicates transfer in progress
Write: Starts a transfer operation
Serial Data Register U (SDRU)
Bit
7 6 5 4 3 2 1 0
SDRU7 SDRU6 SDRU5 SDRU4 SDRU3 SDRU2 SDRU1 SDRU0
Initial value
Undefined Undefined Undefined Undefined Undefined Undefined Undefined Undefined
Read/Write
R/W R/W R/W R/W R/W R/W R/W R/W
SDRU is an 8-bit read/write register. It is used as the data register for the upper 8 bits in 16-bit
transfer (SDRL is used for the lower 8 bits).
Data written to SDRU is output to SDRL starting from the least significant bit (LSB). This data is
then replaced by LSB-first data input at pin SI1, which is shifted in the direction from the most
significant bit (MSB) toward the LSB.
SDRU must be written or read only after data transmission or reception is complete. If this register
is written or read while a data transfer is in progress, the data contents are not guaranteed.
The SDRU value upon reset is undefined.
Serial Data Register L (SDRL)
Bit
7 6 5 4 3 2 1 0
SDRL7 SDRL6 SDRL5 SDRL4 SDRL3 SDRL2 SDRL1 SDRL0
Initial value
Undefined Undefined Undefined Undefined Undefined Undefined Undefined Undefined
Read/Write
R/W R/W R/W R/W R/W R/W R/W R/W
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 ...