HD6433308 HITACHI [Hitachi Semiconductor], HD6433308 Datasheet - Page 212

• Manufacturer Part Number: HD6433308
• Description: Hitachi Single-Chip MicroComputer
• Manufacturer: HITACHI [Hitachi Semiconductor]

(2) Clock: Either the internal serial clock created by the on-chip baud rate generator or an external
clock input at the CSCK pin can be selected in the synchronous mode. See Table 9-6 for details.
(3) Data Transmission and Reception
• SCI Initialization: Before data can be transmitted or received, the SCI must be initialized by
software. To initialize the SCI, software must clear the TE and RE bits to “0” to disable both the
transmit and receive functions, then execute the following procedure.
The TE and RE bits must both be cleared to “0” whenever the operating mode or data format is
changed. After changing the operating mode or data format, before setting the TE and RE bits to
“1” software must wait for at least 1 bit transfer time at the selected communication speed, to make
sure the SCI is initialized.
Serial clock
Write the value corresponding to the desired bit rate in the BRR. (This step is not necessary if
an external clock is used.)
Select the clock and enable desired interrupts in the SCR. Leave bit 0 (CKE0) cleared to "0."
Select the synchronous mode in the SMR.
Set the TE and/or RE bit in the SCR to “1.”
Serial
clock
Data
Data
Don’t-care
Bit 0
Figure 9-4. Data Format in Synchronous Mode
8-Bit data
Bit 1
Bit 2
Bit 3
199
Transmission direction
Bit 4
8-Bit data
Bit 5
Bit 6
Don’t-care
Bit 7