628
Chapter 32 USART (LIN / FIFO)
4.USART Registers
4.4 Reception and Transmission Data Register (RDR04 / TDR04)
The reception data register (RDR04) holds the received data. The transmission data register (TDR04) holds
the transmission data. Both RDR04 and TDR04 registers are located at the same address.
(Note)
TDR04 is a write-only register and RDR04 is a read-only register. These registers are located in the
same address, so the read value is different from the write value. Therefore, instructions that perform
a read-modify-write (RMW) operation, such as the INC/DEC instruction, cannot be used.
Figure 4-4 Transmission and Reception Data registers 04 (RDR04 / TDR04)
■
Reception:
RDR04 is the register that contains reception data. The serial data signal transmitted to the SIN04 pin is
converted in the shift register and stored there. When the data length is 7 bits, the uppermost bit (D7) contains
0. When reception is complete the data is stored in this register and the reception data full flag bit (SSR04:
RDRF) is set to 1. If a reception interrupt request is enabled at this point, a reception interrupt occurs.
Read RDR04 when the RDRF bit of the status register (SSR04) is 1. The RDRF bit is cleared automatically to
0 when RDR04 is read. Also the reception interrupt is cleared if it is enabled and no error has occurred.
Data in RDR04 is invalid when a reception error occurs (SSR04: PE, ORE, or FRE = 1).
■
Transmission:
When data to be transmitted is written to the transmission data register in transmission enable state, it is
transferred to the transmission shift register, then converted to serial data, and transmitted from the serial data
output terminal (SOT04 pin). If the data length is 7 bits, the uppermost bit (D7) is not sent.
When transmission data is written to this register, the transmission data empty flag bit (SSR04: TDRE) is
cleared to 0. When transfer to the transmission shift register is complete, the bit is set to 1. When the TDRE bit
is 1, the next part of transmission data can be written. If output transmission interrupt requests have been
bit8
TIE: Transmission
interrupt request
enable bit
•
This bit enables or disables output of a request for transmission interrupt
to the CPU.
•
A transmission interrupt request is output when this bit and the TDRE bit
are 1.
Table 4-5 Functions of each bit of status register 04 (SSR04)
Bit name
Function
Initial value
0 0 0 0 0 0 0 0
B
R/W R/W R/W R/W
R/W
R/W
R/W R/W
bit8-0
R/W
Data Registers
Read
Read from Reception Data Register
Write
Write to Transmission Data Register
R/W
:
Readable and writable
7
6
5
4
3
2
1
0
Содержание FR Family FR60 Lite
Страница 2: ...FUJITSU LIMITED ...
Страница 3: ...FR60 32 BIT MICROCONTROLLER MB91460 Series User s Manual ...
Страница 15: ...xi ...
Страница 16: ...xii ...
Страница 38: ...22 Chapter 2 MB91460 Rev A Rev B Overview 4 Block Diagram ...
Страница 128: ...112 Chapter 4 CPU Architecture 9 Addressing ...
Страница 153: ...137 Chapter 8 Device State Transition 3 State Transition Diagram ...
Страница 154: ...138 Chapter 8 Device State Transition 3 State Transition Diagram ...
Страница 169: ...153 Chapter 9 Reset 10 Caution ...
Страница 170: ...154 Chapter 9 Reset 10 Caution ...
Страница 180: ...164 Chapter 10 Standby 7 Q A ...
Страница 182: ...166 Chapter 10 Standby 8 Caution ...
Страница 199: ...183 Chapter 12 Instruction Cache 2 Main body structure Figure 2 3 I Cache Address Map ...
Страница 200: ...184 Chapter 12 Instruction Cache 2 Main body structure Figure 2 4 I Cacheable Area ...
Страница 222: ...206 Chapter 13 Clock Control 8 Caution ...
Страница 232: ...216 Chapter 14 PLL Interface 7 Caution ...
Страница 236: ...220 Chapter 15 CAN Clock Prescaler 3 Registers ...
Страница 288: ...272 Chapter 19 Timebase Timer 8 Caution ...
Страница 314: ...298 Chapter 22 Main Oscillation Stabilisation Timer 8 Caution ...
Страница 326: ...310 Chapter 23 Sub Oscillation Stabilisation Timer 8 Caution ...
Страница 348: ...332 Chapter 25 External Interrupt 8 Caution ...
Страница 398: ...382 Chapter 26 DMA Controller 6 DMA External Interface ...
Страница 402: ...386 Chapter 27 Delayed Interrupt 8 Caution ...
Страница 412: ...396 Chapter 28 Bit Search 8 Caution ...
Страница 521: ...505 Chapter 30 I O Ports 3 Port Register Settings ...
Страница 522: ...506 Chapter 30 I O Ports 3 Port Register Settings ...
Страница 549: ...533 Chapter 31 External Bus 2 External Bus Interface Registers is set to the high impedance state ...
Страница 574: ...558 Chapter 31 External Bus 4 Endian and Bus Access Byte Access ...
Страница 628: ...612 Chapter 31 External Bus 13 Notes on Using the External Bus Interface ...
Страница 706: ...690 Chapter 33 I2C Controller 4 Programming Flow Charts ...
Страница 748: ...732 Chapter 34 CAN Controller 4 CAN Application ...
Страница 762: ...746 Chapter 35 Free Run Timer 8 Caution ...
Страница 790: ...774 Chapter 37 Output Compare 8 Caution ...
Страница 838: ...822 Chapter 39 Programmable Pulse Generator 8 Caution ...
Страница 850: ...834 Chapter 40 Pulse Frequency Modulator 4 PFM Operation and Setting ...
Страница 886: ...870 Chapter 42 Sound Generator 3 Registers ...
Страница 900: ...884 Chapter 43 Stepper Motor Controller 4 Caution ...
Страница 939: ...923 Chapter 47 LCD Controller 3 Configuration Figure 3 2 Register List ...
Страница 943: ...927 Chapter 47 LCD Controller 4 Registers Correspondence between VRAM and Common Segment Pins ...
Страница 964: ...948 Chapter 48 Clock Monitor 8 Caution ...
Страница 994: ...978 Chapter 51 Low Voltage Reset Interrupt 3 Registers ...
Страница 998: ...982 Chapter 52 Regulator Control 3 Registers ...
Страница 1008: ...992 Chapter 53 Fixed Mode Reset Vector BOOT ROM 5 Bootloader Update Strategy ...
Страница 1024: ...1008 Chapter 54 Flash Memory 8 Caution ...
Страница 1032: ...1016 Chapter 55 Flash Security 4 Register ...
Страница 1034: ...1018 Chapter 56 Electrical Specification ...
Страница 1035: ...FR60 MB91460 Series Hardware Manual European Microcontroller Design Centre Author MBo ...
Страница 1036: ......
Страница 1038: ......