Z8 ® Cpu Product Overview; Key Features - ZiLOG Z8 Series User Manual

®
Z8 CPU Product Overview
Zilog's Z8
introductions. Zilog MCU products are targeted for cost-sensitive, high-volume applica-
tions including consumer, automotive, security, and HVAC. It includes ROM-based prod-
ucts geared for high-volume production (where software is stable) and one-time
programmable (OTP) equivalents for prototyping as well as volume production where
time to market or code flexibility is critical (see
options are available including plastic DIP, SOIC, PLCC, and QFP.
A generalized Z8 CPU block diagram is displayed in
chip peripherals are used across the MCU product line with the primary differences being
the amount of ROM/RAM, number of I/O lines present, and packaging/temperature
ranges available. This allows code written for one MCU device to be easily ported to
another family member.

Key Features

The key features include:
General-Purpose Register File—
instruction execution and maximizing coding efficiency. Working register groups allow
fast context switching.
Flexible I/O—
software programmable as open-drain or push–pull on a port basis. Inputs are Schmitt-
Triggered with autolatches to hold unused inputs at a known voltage state.
Analog Inputs—
When in analog mode, two comparator inputs are provided with a common reference
input. These inputs are ideal for a variety of common functions, including threshold level
detection, analog-to-digital conversion, and short circuit detection. Each analog input pro-
vides a unique maskable interrupt input.
Timer/Counter—
8-bit downcounter, with maskable interrupt upon end-of-count. Software controls T/C
load/start/stop, countdown read (at any time on the fly), and maskable end-of-count inter-
rupt. Special functions available include T
or external trigger input) and T
clock). These special functions allow accurate hardware input pulse measurement and out-
put waveform generation.
Interrupts—
and priority for each of the six sources.
Watchdog Timer—
mechanism so that if software strays outside the bounds of normal operation, the WDT is
used to time-out and reset the MCU. To maximize circuit robustness and reliability, the
UM001604-0108
®
microcontroller (MCU) product line continues to expand with new product
I/O byte, nibble, and/or bit programmable as inputs or outputs. Outputs are
Three input pins are software programmable as digital or analog inputs.
The Timer/Counter (T/C) consists of a programmable 6-bit prescaler and
OUT
There are six vectored interrupt sources with software-programmable enable
An internal Watchdog Timer (WDT) circuit is included as a fail-safe
Table 1 on page 3). A variety of packaging
Figure 1
Every RAM register acts like an accumulator, speeding
(external counter input, external gate input,
IN
(external access to timer output or the internal system
®
Z8 CPU
User Manual
on page 2. The same on-
®
Z8 CPU Product Overview
1