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ZBasic Language Reference
163
ZX Microcontroller Family
Appendix D - ZX-40 Series Hardware Reference
The ZX-40 series devices are the 40-pin DIP package versions of the respective Atmel AVR ATmega
microcontrollers that have been programmed with the ZX control firmware (for VM mode devices) or a
bootloader (for native mode devices). They offer the same capabilities as the ZX-24 series plus access to
7 additional I/O pins. In order to use the ZX-40 series devices you must add several additional
components as described below. In each of the diagrams presented below, only a portion of the device’s
40 pins is shown. Those that are not germane to the circuit being discussed are omitted for clarity.
D.1 ZX-40 Series Specifications
The electrical specifications of the ZX-40, ZX-40a, ZX-40p, ZX-40n, ZX-40r and ZX-40s are exactly those
of the underlying ATmega microcontrollers. Rather than reproducing them here the reader is directed to
the datasheet published by Atmel. It can be obtained from the Atmel website |http://www.atmel.com or
from the ZBasic website |http://www.zbasic.net.
D.2 ZX-40 Series Required External Components
Power Source
The ZX-40 series devices need a regulated voltage source capable of providing at least 200mA of
current. The voltage typically used is 5 volts but the device will operate between 4.5 volts and 5.5 volts.
A recommended circuit is shown below. A suitable heatsink will probably be required in most cases to
keep the regulator IC below its maximum operating temperature. Consult the regulator datasheet for
more information.
ZX-40 Series Power Source
If you do not plan to use the Analog-to-Digital converter channels you can eliminate the inductor and the
two capacitors on the right side of the diagram. In this case, pin 30 would be connected directly to the
power source (as are pins 10 and 30) and pin 32 can be left open. Although not shown on this diagram,
the ground pins of the ZX-40 (pins 11 and 31) must be connected to the common ground of the system.
Clock Source
The ZX-40 series devices require a clock source running at 14.7456MHz. The easiest way to provide
this clock source is to connect a crystal of that frequency to pins 12 and 13 along with the necessary
capacitors.
The recommended crystal to use is ECS-147.4-20-4 (Digi-Key #X175-ND). Alternate crystals are the
ECS-147.4-20-1 (Digi-Key #X142-ND) in a slightly larger package and the ECS-147.4-18-9 (Digi-Key
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