HD6433935 Hitachi, HD6433935 Datasheet - Page 260

• Manufacturer Part Number: HD6433935
• Description: 8-Bit MICROCONTROLLER
• Manufacturer: Hitachi

Bit 1: Tail mark transmission flag (MTRF)
When MRKON = 1, bit 1 indicates that a tail mark is being transmitted. MTRF is a read-only bit,
and cannot be modified.
Bit 1
MTRF
0
1
Bit 0: Start flag (STF)
The STF bit controls the start of transfer operations. SCI1 transfer operation is started when this
bit is set to 1.
STF remains set to 1 during transfer and while SCI1 is waiting for a start bit, and is cleared to 0
when transfer ends.
Bit 0
STF
0
1
3. Serial data register U (SDRU)
SDRU is an 8-bit read/write register used as the data register for the upper 8 bits in 16-bit transfer
(while SDRL is used for the lower 8 bits).
The data written into SDRU is output to SDRL in LSB-first order. In the replacement process, data
is input LSB-first from the SI
SDRU read/write operations must only be performed after data transmission/reception has been
completed. Data contents are not guaranteed if read/write operations are executed while data
transmission/reception is in progress.
The value of SDRU is undefined upon reset.
248
Bit
Initial value
Read/Write
Description
Idle state, or 8-bit/16-bit data transfer in progress
Tail mark transmission in progress
Description
Read
Write
Read
Write
Undefined
SDRU7
R/W
7
Transfer operation stopped
Invalid
Transfer operation in progress
Starts transfer operation
Undefined
SDRU6
1
R/W
pin, and the data is shifted in the MSB
6
Undefined
SDRU5
R/W
5
Undefined
SDRU4
R/W
4
Undefined
SDRU3
R/W
3
Undefined
SDRU2
R/W
2
LSB direction.
Undefined
SDRU1
R/W
1
(initial value)
(initial value)
Undefined
SDRU0
R/W
0