Renesas H8 Series Hardware Manual page 420

Section 10 Serial Communication Interface
Sets bit SPC32 to
1 in SPCR
Read bit TDRE
TDRE = 1?
Set bit MPBT
Write transmit
data to TDR
Continue data
transmission?
Read bit TEND
TEND = 1?
Break output?
Set PDR = 0,
Clear bit TE to
0 in SCR3
Figure 10.17 Example of Multiprocessor Data Transmission Flowchart
Rev. 7.00 Mar 10, 2005 page 378 of 652
REJ09B0042-0700
Start
[1]
in SSR
No
Yes
in SSR
[2]
Yes
No
in SSR
No
Yes
[3]
No
Yes
PCR = 1
End
[1] Read the serial status register (SSR)
and check that bit TDRE is set to 1,
then set bit MPBT in SSR to 0 or 1 and
write transmit data to the transmit data
register (TDR). When data is written to
TDR, bit TDRE is cleared to 0 automatically.
[2] When continuing data transmission, be
sure to read TDRE = 1 to confirm that a
write can be performed before writing data
to TDR. When data is written to TDR, bit
TDRE is cleared to 0 automatically.
[3] If a break is to be output when data
transmission ends, set the port PCR to 1
and clear the port PDR to 0, then clear bit
TE in SCR3 to 0.