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Section 10 Serial Communication Interface
Rev. 6.00 Sep 12, 2006 page 285 of 526
REJ09B0326-0600
Data Transfer Operations
Transmitting:
A transmit operation is carried out as follows.
1. Set bits SO1 and SCK1 to 1 in PMR3 to select the SO
1
and SCK
1
pin functions. If necessary,
set bit POF1 in PMR7 for NMOS open-drain output at pin SO
1
.
2. Clear bit SNC1 in SCR1 to 0, set bit SNC0 to 0 or 1, and clear bit MRKON to 0, designating
8- or 16-bit synchronous transfer mode. Select the serial clock in bits CKS3 to CKS0. Writing
data to SCR1 when bit MRKON in SCR1 is cleared to 0 initializes the internal state of SCI1.
3. Write transmit data in SDRL and SDRU, as follows.
8-bit transfer mode: SDRL
16-bit transfer mode: Upper byte in SDRU, lower byte in SDRL
4. Set the SCSR1 start flag (STF) to 1. SCI1 starts operating and outputs transmit data at pin SO
1
.
5. After data transmission is complete, bit IRRS1 in interrupt request register 2 (IRR2) is
set to 1.
When an internal clock is used, a serial clock is output from pin SCK
1
in synchronization with the
transmit data. After data transmission is complete, the serial clock is not output until the next time
the start flag is set to 1. During this time, pin SO
1
continues to output the value of the last bit
transmitted.
When an external clock is used, data is transmitted in synchronization with the serial clock input at
pin SCK
1
. After data transmission is complete, an overrun occurs if the serial clock continues to be
input; no data is transmitted and the SCSR1 overrun error flag (bit ORER) is set to 1.
While transmission is stopped, the output value of pin SO
1
can be changed by rewriting bit SOL in
SCSR1.
Receiving:
A receive operation is carried out as follows.
1. Set bits SI1 and SCK1 to 1 in PMR3 to select the SI
1
and SCK
1
pin functions.
2. Clear bit SNC1 in SCR1 to 0, set bit SNC0 to 0 or 1, and clear bit MRKON to 0, designating
8- or 16-bit synchronous transfer mode. Select the serial clock in bits CKS3 to CKS0. Writing
data to SCR1 when bit MRKON in SCR1 is cleared to 0 initializes the internal state of SCI1.
3. Set the SCSR1 start flag (STF) to 1. SCI1 starts operating and receives data at pin SI
1
.
4. After data reception is complete, bit IRRS1 in interrupt request register 2 (IRR2) is set to 1.
5. Read the received data from SDRL and SDRU, as follows.
8-bit transfer mode: SDRL
16-bit transfer mode: Upper byte in SDRU, lower byte in SDRL
Содержание F-ZTAT H8/3642A Series
Страница 6: ...Rev 6 00 Sep 12 2006 page iv of xx ...
Страница 8: ...Rev 6 00 Sep 12 2006 page vi of xx ...
Страница 21: ...Rev 6 00 Sep 12 2006 page xix of xx Appendix E Product Code Lineup 522 Appendix F Package Dimensions 524 ...
Страница 22: ...Rev 6 00 Sep 12 2006 page xx of xx ...
Страница 124: ...Section 5 Power Down Modes Rev 6 00 Sep 12 2006 page 102 of 526 REJ09B0326 0600 ...
Страница 188: ...Section 6 ROM Rev 6 00 Sep 12 2006 page 166 of 526 REJ09B0326 0600 ...
Страница 190: ...Section 7 RAM Rev 6 00 Sep 12 2006 page 168 of 526 REJ09B0326 0600 ...
Страница 298: ...Section 9 Timers Rev 6 00 Sep 12 2006 page 276 of 526 REJ09B0326 0600 ...
Страница 378: ...Section 12 A D Converter Rev 6 00 Sep 12 2006 page 356 of 526 REJ09B0326 0600 ...
Страница 446: ...Section 13 Electrical Characteristics Rev 6 00 Sep 12 2006 page 424 of 526 REJ09B0326 0600 ...