SH7205 Datasheet, PDF (865/1904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 17 Synchronous Serial Communication Unit (SSU)
Start
[1]
Initial setting
[2]
Read the TDRE bit in SSSR
No
TDRE = 1?
Yes
Write transmit data to SSTDR
TDRE automatically cleared
Data transferred from SSTDR to SSTRSR
Set TDRE to 1 to start transmission
[3]
Consecutive data transmission?
Yes
No
Read the TEND bit in SSSR
No
TEND = 1?
Yes
Clear the TEND bit to 0
[1] Initial setting:
Specify the transmit data format.
[2] Check that the SSU state and write transmit data:
Write transmit data to SSTDR after reading and confirming
that the TDRE bit is 1. The TDRE bit is automatically cleared
to 0 and transmission is started by writing data to SSTDR.
[3] Procedure for consecutive data transmission:
To continue data transmission, confirm that the TDRE bit is 1
meaning that SSTDR is ready to be written to. After that, data
can be written to SSTDR. The TDRE bit is automatically
cleared to 0 by writing data to SSTDR.
[4] Procedure for data transmission end:
To end data transmission, confirm that the TEND bit is cleared
to 0. After completion of transmitting the last bit, clear the TE
bit to 0.
Confirm that the TEND bit is cleared to 0
[4]
One bit time
No
quantum elapsed?
Yes
Clear the TE bit in SSER to 0
End transmission
Note: Hatching boxes represent SSU internal operations.
Figure 17.14 Flowchart Example of Transmission Operation
(Clock Synchronous Communication Mode)
Rev. 1.00 Mar. 25, 2008 Page 833 of 1868
REJ09B0372-0100