Z86E04 Datasheet, PDF (20/44 Pages) Zilog, Inc. – CMOS Z8 OTP MICROCONTROLLERS

Z86E04/E08
CMOS Z8 OTP Microcontrollers
Zilog
PIN FUNCTIONS (Continued)
XTAL1, XTAL2 Crystal In, Crystal Out (time-based input
and output, respectively). These pins connect a parallel-
resonant crystal, LC, or an external single-phase clock
(8 MHz or 12 MHz max) to the on-chip clock oscillator and
buffer.
Port 0, P02–P00. Port 0 is a 3-bit bidirectional, Schmitt-
triggered CMOS-compatible I/O port. These three I/O lines
can be globally configured under software control to be in-
puts or outputs (Figure 7).
Auto Latch. The Auto Latch puts valid CMOS levels on all
CMOS inputs (except P33, P32, P31) that are not external-
ly driven. A valid CMOS level, rather than a floating node,
reduces excessive supply current flow in the input buffer.
On Power-up and Reset, the Auto Latch will set the ports
to an undetermined state of 0 or 1. Default condition is
Auto Latches enabled.
Z8
Port 0 (I/O)
OE
Out
1.5
2.3 Hysteresis VCC@ 5.0V
In
R 500 kΩ
Figure 7. Port 0 Configuration
20
PRELIMINARY
PAD
Auto Latch Option
DS97Z8X1104