h8s-2628 Renesas Electronics Corporation., h8s-2628 Datasheet - Page 389

• Manufacturer Part Number: h8s-2628
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

14.6.3
Figure 14.16 shows an example of SCI operation for transmission in clocked synchronous mode.
In serial transmission, the SCI operates as described below.
1. The SCI monitors the TDRE flag in SSR, and if the flag is 0, the SCI recognizes that data has
2. After transferring data from TDR to TSR, the SCI sets the TDRE flag to 1 and starts
3. 8-bit data is sent from the TxD pin synchronized with the output clock when output clock
4. The SCI checks the TDRE flag at the timing for sending the MSB (bit 7).
5. If the TDRE flag is cleared to 0, data is transferred from TDR to TSR, and serial transmission
6. If the TDRE flag is set to 1, the TEND flag in SSR is set to 1, and the TDRE flag maintains the
Figure 14.17 shows a sample flow chart for serial data transmission. Even if the TDRE flag is
cleared to 0, transmission will not start while a receive error flag (ORER, FER, or PER) is set to 1.
Make sure that the receive error flags are cleared to 0 before starting transmission. Note that
clearing the RE bit to 0 does not clear the receive error flags.
been written to TDR, and transfers the data from TDR to TSR.
transmission. If the TIE bit in SCR is set to 1 at this time, a transmit data empty interrupt (TXI)
is generated. Continuous transmission is possible because the TXI interrupt routine writes the
next transmit data to TDR before transmission of the current transmit data has been completed.
mode has been specified, and synchronized with the input clock when use of an external clock
has been specified.
of the next frame is started.
output state of the last bit. If the TEIE bit in SCR is set to 1 at this time, a TEI interrupt request
is generated. The SCK pin is fixed high.
Serial Data Transmission (Clocked Synchronous Mode)
Section 14 Serial Communication Interface (SCI)
Rev. 3.00 Oct 04, 2005 page 349 of 598
REJ09B0155-0300