Fig. 5.5.10 Flowchart Of Data Input Processing Routine - Renesas 7200 Series User Manual

APPLICATION
5.5 Example of I 2
(7) Data input processing routine

Fig. 5.5.10 Flowchart of data input processing routine

5-32
C-BUS control by software (M37220M3-XXXSP/FP)
Bit 0 of port P2 direction register
"BIT COUNTER" = "0"
P2
Rotate "READDATA"
P2 (SCL) = "1"
1
"BIT COUNTER"
No
7220 Group User's Manual
Data intput
= "input mode"
(SCL) = "1"
1
Wait 6 µ s
P2 (SDA) = "1"?
0
Yes
Carry flag = "1"
with Carry flag, to left
←"BIT COUNTER" + 1
"BIT COUNTER"
≥ "8"?
Yes
RETURN
RAM: READDATA
BIT COUNTER
No
Carry flag = "0"