7702 datasheet(23/217 Pages) RENESAS

23 / 217 page

DESCRIPTION

7702/7703 Group User’s Manual

1–9

1.3 Pin description

1.3.1 Example for processing unused pins

Examples for processing unused pins are described below. These descriptions are just examples. The user

shall modify them according to the user’s actual application and test them.

(1)

In single-chip mode

Table 1.3.4 Example for processing unused pins in single-chip mode

Example of processing

Set for input mode and connect these pins to Vcc or

Vss via a resistor; or set for output mode and leave

these pins open. (Notes 1, 3)

Leave it open.

Connect this pin to Vcc.

Connect these pins to Vss.

Pin name

Ports P0 to P8

XOUT (Note 2)

AVcc

AVss, VREF, BYTE

Notes 1: When setting these ports to the output mode and leave them open, they remain set to the input

mode until they are switched to the output mode by software after reset. While ports remain set

to the input mode, consequently, voltage levels of pins are unstable, and a power source current

can increase.

The contents of the direction register can be changed by noise or a program runaway generated

by noise. To improve its reliability, we recommend to periodically set the contents of the direction

When processing unused pins, use the possible shortest wiring (within 20 mm from the microcomputer).

2: This applies when a clock externally generated is input to the XIN pin.

3: In the 7703 Group, the following ports does not have the corresponding pins and have only the

direction registers. Fix the bit of these direction registers to “1” (output mode).

•Ports P33, P43–P46, P60, P61, P66, P67, P73–P76, P84, P85

P0–P8

AVSS

VREF

BYTE

VSS

AVCC

XOUT

VCC

P0–P8

AVSS

VREF

VSS

AVCC

XOUT

VCC

Left open

q When setting ports for input mode

q When setting ports for output mode

Left open

BYTE

Fig. 1.3.1 Example for processing unused pins in single-chip mode

7702 Datasheet(PDF) 23 Page - Renesas Technology Corp

7702 Datasheet(HTML) 23 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