SH7147 Datasheet, PDF (615/1108 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH™ RISC engine Family

Section 13 Serial Communication Interface (SCI)
13.7.6 Note on Using DTC
When the external clock source is used for the clock for synchronization, input the external clock
after waiting for five or more cycles of the peripheral operating clock after SCTDR is modified
through the DTC. If a transmit clock is input within four cycles after SCTDR is modified, a
malfunction may occur (figure 13.22).
SCK
t
TDRE
TXD
D0
D1
D2
D3
D4
D5
D6
D7
Note: When using the external clock, t must be set to larger than 4 cycles.
Figure 13.22 Example of Clock Synchronous Transfer Using DTC
When data is written to SCTDR by activating the DTC by a TXI interrupt, the TEND flag value
becomes undefined. In this case, do not use the TEND flag as the transmit end flag.
13.7.7 Note on Using External Clock in Clock Synchronous Mode
TE and RE must be set to 1 after waiting for four or more cycles of the peripheral operating clock
after the SCK external clock is changed from 0 to 1.
TE and RE must be set to 1 only while the SCK external clock is 1.
13.7.8 Module Standby Mode Setting
SCI operation can be disabled or enabled using the standby control register. The initial setting is
for SCI operation to be halted. Register access is enabled by clearing module standby mode. For
details, refer to section 22, Power-Down Modes.
Rev. 3.00 Oct. 06, 2008 Page 591 of 1080
REJ09B0230-0300