ZiLOG Z8 Series User Manual

Z8
®
CPU
User Manual
UM001604-0108 Input/Output Ports
76
On CMOS OTP EPROM Z8
®
MCUs, the Port 3 inputs P31, P32, P33, and the XTAL 1
pin have only the input protection diode from pad to V
SS
. See Figure 64.
The high-side input protection diodes were removed on these pins to allow the application
of +12.5 V during the various OTP programming modes.
For better noise immunity in applications that are exposed to system EMI, a clamping
diode to V
CC
from these pins may be required to prevent entering the OTP programming
mode or to prevent high voltage from damaging these pins.
Figure 63. Diode Input Protection
Figure 64. OTP Diode Input Protection
PIN
V
CC
V
SS
PIN
V
SS

ZiLOG Z8 Series Specifications

General

Brand	ZiLOG
Model	Z8 Series
Category	Microcontrollers
Language	English