Renesas RL78/G1P Hardware User Manual page 386

RL78/G1P
Figure 11-47. Flowchart of Master Transmission/Reception (in Continuous Transmission/Reception Mode)
Write MDmn0 bit to 1
Remark <1> to <8> in the figure correspond to <1> to <8> in Figure 11-46
Transmission/Reception (in Continuous Transmission/Reception Mode).
R01UH0895EJ0100 Rev.1.00
Nov 29, 2019
Starting setting
SAU default setting
<1>
Setting
transmission/reception data
Enables interrupt
Writing dummy data to
<2>
SIOp (= SDRmn [7:0])
Wait for transmission/
reception completes
<3><6>
Buffer empty/transfer end interrupt
BFFmn = 1?
Yes
<4>
Reading reception data to
SIOp (= SDRmn [7:0])
<7>
Subtract -1 from number of
transmit data
= 0
Number of
communication data?
≥ 2
Writing transmit data to
SIOp (= SDRmn [7:0])
RETI
No
Number of communication
data = 0?
Yes
Yes
Continuing Communication?
No
Disable interrupt (MASK)
<8> Write STmn bit to 1
End of communication
CHAPTER 11 SERIAL ARRAY UNIT
For the initial setting, refer to Figure 11-41.
(Select buffer empty interrupt)
Setting storage data and number of data for transmission/reception
data
(Storage area, Transmission data pointer, Reception data, Number
of communication data and Communication end flag are optionally
set on the internal RAM by the software)
Clear interrupt request flag (XXIF), reset interrupt mask
(XXMK) and set interrupt enable (EI)
Read transmit data from storage area and write it
to SIOp. Update transmit data pointer.
When transmission/reception interrupt is
generated, it moves to interrupt processing
routine
No
Except for initial interrupt, read data received
then write them to storage area, and update
receive data pointer
If transmit data is left (number of communication
data is equal or grater than 2), read them from
storage area then write into SIOp, and update
= 1
transmit data pointer.
If it's waiting for the last data to receive (number of
communication data is equal to 1), change
interrupt timing to communication end
<5>
Clear MDmn0 bit to 0
Writing to SIOp makes
Sop and SCKp signals out
(communication starts)
Timing Chart of Master
367