7220 datasheet(203/303 Pages) RENESAS

203 / 303 page

5-30

APPLICATION

5.5 Example of I2C-BUS control by software (M37220M3-XXXSP/FP)

7220 Group User’s Manual

(3)

Data output processing routine

The data output, the START condition, the STOP condition, and the bus H processing routines are

the common routines within the transmit/receive processing routine.

Data output

Bit 0 of port P2 direction register

“output mode”

“BIT COUNTER” = “0”

Carry flag = “1”?

RETURN

Yes

RAM:

Flag:

WRITEDATA

BIT COUNTER

F_ACK

Rotate “WRITEDATA” left

with Carry flag

P20 (SDA) = “1”

“BIT COUNTER”

≥ “8”?

P20 (SDA) = “0”

P21 (SCL) = “1”

Wait 6

µs

P21 (SCL) = “0”

“BIT COUNTER”

←“BIT COUNTER” + 1

Bit 0 of port P2 direction register

“input mode

Wait 6

µs

P21 (SCL) = “1”

Wait 6

µs

P20 (SDA) = “1”?

Yes

F_ACK = “1”

F_ACK = “0”

P21 (SCL) = “0”

Yes

Fig. 5.5.6 Flowchart of data output processing routine

7220 Datasheet(PDF) 203 Page - Renesas Technology Corp

7220 Datasheet(HTML) 203 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL