SH7760 Datasheet, PDF (677/1345 Pages) Renesas Technology Corp – SuperHTM RISC engine

(2) Serial data transmission
Data transmission in smart card mode includes error signal sampling and repetition processing.
An example of transmission processing is shown in figure 18.5.
Initialization
(1)
Start transmission
No
(2)
ERS=0?
Yes
Error processing
No
TDRE=1?
(3)
Yes
Write transmission data to SITDR (4)
No
All data transmitted?
(5)
Yes
No
ERS=0?
Yes
Error processing
No
TEND=1&&
TDRE=1?
Yes
Clear TE bit in SISCR to 0
(6)
(1) Follow the procedure of item 1 in section 18.4.4,
and initialize the smart card interface.
(2) Confirm that the ERS bit (error flag) in SISSR is
cleared to 0.
(3) _{Repeat (2) and (3) in the figure until it can be}
confirmed that the TDRE flag in SISSR is set to 1.
(4) Write the transmission data to SITDR, and
perform the transmission. At this time, the TDRE
flag is automatically cleared to 0. When
transmission of the start bit is begun, the TEND
flag is automatically cleared to 0, and the TDRE
flag is automatically set to 1.
(5) When performing continuous data transmission,
return to (2).
(6) _{When transmission is ended, clear the TE bit to 0.}
Transmission end
Figure 18.5 Example of Transmission Processing
Rev. 1.0,02/03, page 627 of 1294