323
CHAPTER 14 8-BIT SERIAL I/O
14.4.2
Serial Data Register (SDR)
The serial data register (SDR) retains 8-bit serial I/O transfer data. The SDR functions as
a transmission data register at serial output operation. It functions as a reception data
register at serial input operation.
■
Serial Data Register (SDR)
Figure 14.4-3 shows the bit structure of the SDR.
Figure 14.4-3 Serial Data Register (SDR)
●
At serial output operation
The SDR functions as a transmission data register at serial output operation. When serial I/O transfer is
started (SMR: SST = 1), the 8-bit serial data written to the SDR is transferred. Transmission data does not
remain in the SDR because it is shifted out via serial I/O transfer.
●
At serial input operation
The SDR functions as a reception data register. When serial I/O transfer is started (SMR: SST = 1), the
serially transferred reception data is stored in the SDR.
●
When the serial I/O is in transfer operation
When the serial I/O is in transfer operation, do not write data to the SDR. Moreover, note that the read
values have no significance.
When serial output and serial input are allowed at the same time, serial I/O operation is performed.
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
003A
H
XXXXXXXX
B
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
: Readable and Writable
X
: Undefined
Address
Initial value
Содержание F2MC-8L F202RA
Страница 2: ......
Страница 4: ......
Страница 32: ...16 CHAPTER 1 OVERVIEW ...
Страница 90: ...74 CHAPTER 3 CPU ...
Страница 142: ...126 CHAPTER 5 TIME BASE TIMER POPW A RETI ENDS END ...
Страница 150: ...134 CHAPTER 6 WATCHDOG TIMER ...
Страница 174: ...158 CHAPTER 7 8 BIT PWM TIMER User processing POPW A XCHW A T Restoring A and T POPW A RETI ENDS ...
Страница 176: ...160 CHAPTER 7 8 BIT PWM TIMER ...
Страница 220: ...204 CHAPTER 8 8 16 BIT CAPTURE TIMER COUNTER ...
Страница 240: ...224 CHAPTER 9 12 BIT PPG TIMER ...
Страница 258: ...242 CHAPTER 10 EXTERNAL INTERRUPT CIRCUIT 1 EDGE PUSHW A User processing POPW A XCHW A T POPW A RETI ENDS END ...
Страница 274: ...258 CHAPTER 11 EXTERNAL INTERRUPT CIRCUIT 2 LEVEL ...
Страница 362: ...346 CHAPTER 15 BUZZER OUTPUT ...
Страница 371: ...355 CHAPTER 16 WILD REGISTER FUNCTION 16 3 5 Data Test Set Register WROR A test register Do not access this register ...
Страница 390: ...374 CHAPTER 17 FLASH MEMORY ...
Страница 419: ...403 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Страница 434: ...418 INDEX ...
Страница 436: ......