7220 datasheet(50/303 Pages) RENESAS

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2-23

FUNCTIONAL DESCRIPTION

2.4 Input/Output pins

7220 Group User’s Manual

2.4.2 Dedicated pins

(1)

14-bit PWM output (D-A) pin

This is a 14-bit PWM signal output pin. This pin also can be used for 1-bit general-purpose output

port. The output structure is CMOS output.

(2)

Vertical and horizontal synchronous signal input pins (VSYNC, HSYNC)

These pins input the vertical and horizontal synchronous signals for CRT display.

(3)

Test input pin (CNVSS)

Connect this pin to VSS.

(4)

Reset input pin (RESET)

This pin inputs reset signal. To reset the microcomputer, hold the RESET pin at a LOW level for

µs or more. Reset is released when HIGH level is applied to the RESET pin. For details, refer to

“2.15 Reset.”

(5)

Clock I/O pins (XIN, XOUT)

These pins are I/O pins of main clock f(XIN). Since a microcomputer has on-chip clock oscillation

circuit, set the oscillation frequency by connecting an external ceramic resonator or a quartz-crystal

oscillator between pins XIN and XOUT.

When inputting an external clock, connect the external clock to the XIN pin and leave the XOUT pin

open.

The output structure of XOUT pin is CMOS output.

(6)

Power source input pin (VCC, VSS)

These pins supply the power source to a microcomputer. Apply voltage of 5 V ± 10 % to pin VCC and

0 V to pin VSS.

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