Z86C04 Datasheet, PDF (18/34 Pages) Zilog, Inc. – CMOS 8-BIT LOW-COST 1K/2K-ROM MICROCONTROLLERS

Z86C04/C08
CMOS 8-Bit Low-Cost 1K/2K-ROM Microcontrollers
PIN DESCRIPTION
XTAL1, XTAL2 Crystal In, Crystal Out (time-based input
and output, respectively). These pins connect a RC, paral-
lel-resonant crystal, LC, or an external single-phase clock
to the on-chip clock oscillator and buffer.
Auto Latch. The Auto Latch puts valid CMOS levels on all
CMOS inputs (except P33, P32, P31) that are not external-
ly driven. After Power-On Reset, this level is 0 or 1 cannot
be determined. A valid CMOS level, rather than a floating
Zilog
node, reduces excessive supply current flow in the input
buffer. To change the Auto Latch state, the auto latches
must be over driven with current greater than I_ALH (high to
low) or I_ALL (low to high).
Port 0 (P02-P00). Port 0 is a 3-bit I/O, bidirectional,
Schmitt-triggered CMOS compatible I/O port. These three
I/O lines can be configured under software control to be all
inputs or all outputs (Figure 7).
Z86E04
and
Z86E08
Port 0 (I/O)
Open
PAD
Out
1.5
2.3 Hysteresis VCC @ 5.0V
In
R 500 kΩ
Figure 6. Port 0 Configuration
Auto Latch Option
18
PRELIMINARY
DS97DZ80502