r5f71374an80fpv Renesas Electronics Corporation., r5f71374an80fpv Datasheet - Page 639

• Manufacturer Part Number: r5f71374an80fpv
• Description: 32-bit Risc Microcomputer Superh?? Risc Engine Family
• Manufacturer: Renesas Electronics Corporation.

15.3.7
SSTDR is an 8-bit register that stores transmit data. When 8-bit data length is selected by bits
DATS1 and DATS0 in SSCRL, SSTDR0 is valid. When 16-bit data length is selected, SSTDR0
and SSTDR1 are valid. When 32-bit data length is selected, SSTDR0 to SSTDR3 are valid. Do not
access SSTDR that is not valid.
When the SSU detects that SSTRSR is empty, it transfers the transmit data written in SSTDR to
SSTRSR and starts serial transmission. If the next transmit data has already been written to
SSTDR during serial transmission, the SSU performs consecutive serial transmission.
Although SSTDR can always be read from or written to by the CPU and DTC, to achieve reliable
serial transmission, write transmit data to SSTDR after confirming that the TDRE bit in SSSR is
set to 1.
Table 15.3 Setting of DATS Bits in SSCRL and Corresponding SSTDR
Bit
7 to 0
SSTDR0
SSTDR1
SSTDR2
SSTDR3
Bit Name
SS Transmit Data Registers 0 to 3 (SSTDR0 to SSTDR3)
00
Valid
Invalid
Invalid
Invalid
Initial value:
Initial
Value
All 0
R/W:
Bit:
R/W
R/W
R/W
7
0
01
Valid
Valid
Invalid
Invalid
R/W
6
0
Description
Serial transmit data
R/W
5
0
Section 15 Synchronous Serial Communication Unit (SSU)
DATS[1:0] Setting
R/W
4
0
R/W
3
0
10
Valid
Valid
Valid
Valid
Rev. 1.00 Sep. 21, 2007 Page 613 of 1124
R/W
2
0
R/W
1
0
R/W
0
0
11 (Invalid setting)
Invalid
Invalid
Invalid
Invalid
REJ09B0402-0100