UPD70F3218 Datasheet, PDF (549/884 Pages) NEC – 32-Bit Single-Chip Microcontrollers

CHAPTER 19 I²C BUS
To use the I²C bus function, set the P38/SDA0, P39/SCL0, P80/SDA1, and P81/SCL1 pins to N-ch open
drain output as the alternate function.
In the V850ES/KJ1, two channels of I²C bus are provided.
The products with an on-chip I²C bus are shown below.
µPD703216Y, 703217Y, 70F3217Y, 70F3217HY, 70F3218HY
19.1 Selecting UART2 or I²C1 Mode
UART2 and I²C1 of the V850ES/KJ1 share pins, and therefore these interfaces cannot be used at the same time.
Select UART2 or I²C1 in advance by using the PMC8 and PFC8 registers (refer to 4.3.8 Port 8).
Caution UART2 or I²C1 transmission/reception operations are not guaranteed if the mode is changed during
transmission or reception. Be sure to disable the operation of the unit that is not used.
Figure 19-1. Selecting Mode of UART2 or I²C1
After reset: 00H R/W Address: FFFFF450H
7
6
5
4
3
PMC8
0
0
0
0
0
2
1
0
0
PMC81 PMC80
After reset: 00H R/W Address: FFFFF470H
7
6
5
4
3
PFC8
0
0
0
0
0
2
1
0
0
PFC81 PFC80
PFC8n
0
0
1
1
PMC8n
0
1
0
1
Operation mode
Port I/O mode
UART2 mode
Port I/O mode
I²C1 mode
Remark n = 0, 1
User’s Manual U16889EJ1V0UD
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