Z86L79 Datasheet, PDF (13/58 Pages) Zilog, Inc. – Low-Voltage Microcontroller

Zilog
Z86L79/80
Low-Voltage Microcontroller
PIN FUNCTIONS
XTAL1 Crystal 1 (time-based input). This pin connects a Using single trip point ROM mask option, Port 00-03 can
1 ^{parallel-resonant crystal, ceramic resonator, LC, or RC be programmed to allow direct interface to applications}
network or an external single-phase clock to the on-chip that require single point comparison like mouse/trackball
oscillator input.
IR sensors. ROM mask option will enable the 0.4 V_DD trip
Point Buffers on these inputs.
XTAL2 Crystal 2 (time-based output). This pin connects a
parallel-resonant, crystal, ceramic resonant, LC, or RC An optional 200 kOhms (port wide) pull-up is available as
network to the on-chip oscillator output.
a mask option on all bits for the L79/L80 versions.
Port 0 (P07-P00). Port 0 is an 8-bit, bidirectional, CMOS
compatible port. These eight I/O lines are configured un-
der software control as a nibble I/O port. The output drivers
are push-pull in this configuration.
These pull-ups are disabled when configured (bit by
bit) as an output.
4
Z86L7X
MCU
4
Port 0 I/O
OEN
Out
In
0.5 VDD
Trip Point Buffer
In
**
0.4 VDD
Trip Point Buffer
**Mask Selectable
Figure 9. Port 0 Configuration
PRELIMINARY
Mask
Option
200 kΩ
PAD
3-13