ZBasic Language Reference
175
ZBasic Microcontrollers
Appendix D - ZX-24 Series Hardware Reference
The ZX-24 series devices comprise an Atmel AVR ATmega microcontroller along with some support
circuitry on a 24-pin module that is simple to connect for operation. The primary difference between the
members of the ZX-24 series devices is specific ATmega or ATxmega microcontroller used and the
amount of RAM, EEPROM and Program Memory available for use by your programs. The table below
summarizes the differences.
ZX-24 Series Devices
Device
Base AVR
Microcontroller
Mode
RAM
Persistent
Memory
Program
Memory
Operating
Frequency
Operating
Voltage
ZX-24
ATmega32
VM
1536
992
32K
14.7MHz
3.6-5.5V
ZX-24a
ATmega644
VM
3584
2016
32K
14.7MHz
3.6-5.5V
ZX-24p
ATmega644P
VM
3584
2016
32K
14.7MHz
3.6-5.5V
ZX-24n
ATmega644P
Native
4096
2016
62K
14.7MHz
3.6-5.5V
ZX-24r
ATmega1284P
VM
15744
4064
60K
14.7MHz
3.6-5.5V
ZX-24s
ATmega1284P
Native
16384
4064
124K
14.7MHz
3.6-5.5V
ZX-24t
ATmega1284P
Native
16384
4064
124K
7.37MHz
2.3-5.5V
ZX-24x
ATxmega32A4
Native
4096
1024
32K
29.5MHz
2.6-3.6V
ZX-24u
ATxmega128A4U
Native
8192
2048
128K
29.5MHz
2.6-3.6V
The ZX-24 series devices have other resources available to your program including a high-speed serial
port, analog-to-digital converters, timers and other sub-systems that may be accessed using routines in
the ZBasic System Library. Alternately, some of the resources may be accessed directly using built-in
registers. See Section 3.7.1 for more information on this topic.
D.1 External Connections
The ZX-24 series devices can be hooked up in several different ways depending on your requirements.
The simplest method is depicted below. The connector on the left is the serial connection to your PC for
downloading code and transmitting/receiving data on serial channel 1. The connection to pin 3 of the
ZX-24 series is only needed for downloading. You may wish to add a jumper in that line so that it may be
disconnected for “normal” operation. Some operating systems, notably Windows XP, toggle the DTR line
(pin 4 of the DB-9) on the serial ports during boot up. This will cause the ZX to reset on every positive-
going transition of the DTR line.
Simple ZX-24 Series Interconnection
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