The ZX-328n is a low cost 28-pin DIP "native mode" ZX device intended for those who want
to get started using ZX devices on a budget.
It may also be useful for simpler projects that require fewer I/O pins and less program space.
The heart of the ZX-328n is the Atmel AVR ATmega328P microcontroller running at 14.7MHz
which provides 2048 bytes of RAM and 992 bytes of EEPROM available for your programs.
The 32K byte internal Flash memory of the mega328P is partially occupied by special
serial downloader firmware leaving 30K bytes of Flash memory for your application.
The mega328P has 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 these resources may be accessed directly using built-in registers.
To use the ZX-328n you'll need a regulated voltage source (4.5 to 5.5VDC), a 14.7456MHz
crystal and a few additional interface components.
You may download a schematic with suggested support circuitry for the ZX-328n as a
PDF
or as an ExpressPCB .sch file.
To view the latter, you'll have to download free software from
ExpressPCB.
ZX-328n Technical Features
| Package |
28-pin DIP |
| Operating Temperature |
-40 to +85°C |
| Processor |
Atmel AVR ATmega328P |
| Power Requirements |
4.5 to 5.5VDC regulated at 200mA |
| Processor Speed |
Up to 14.7MIPS (14.7MHz) |
| Program Execution Speed |
Up to 2.9 million instructions/sec¹ |
| User RAM |
2K bytes |
| Non-volatile Data Memory |
992 bytes |
| Program Memory |
30K bytes |
| Digital I/O pins |
18+2² |
| Analog-to-Digital Channels |
Up to 6 channels, 10-bit resolution |
| I2C Support |
1 HW channel, 4 SW channels |
| PWM Channels |
Two 16-bit, two 8-bit |
| 1-Wire Support |
Bit and byte level |
| SPI Support |
4 HW channels |
| Synchronous Serial I/O Support |
1-16 bits, MSB or LSB first |
| Asynchronous Serial I/O Ports |
1-HW, up to 4 SW full duplex |
| X-10 Command Support |
Yes |
| Multi-tasking Support |
Yes |
| External Interrupts |
2 |
| Pin Change Interrupts |
All I/O lines |
| Analog Comparator Interrupt |
Yes |
| Interval Timer |
Yes |
| Exception Handling Support |
Yes |
| Floating Point Math |
Yes - IEEE 32-bit |
| Advanced Floating Point
Functions (sin, cos, log, etc.) |
Yes |
| Programming Interface |
Serial - 115.2K baud |
| Field Upgradeable System Software |
No |
| Supports Inline Assembly Code |
Yes |
| Supports Interrupt Handling Code |
Yes |
Notes:
1) Speed based on the instruction b = b + 1.
2) The additional 2 I/O lines are dedicated for serial I/O.
Specifications subject to correction and change without notice.
|
A standard serial port is required to download code to the ZX-328n.
If your computer does not have a standard 9-pin serial port but does have a USB port, you may use a USB to serial adapter.
Note, however, that some USB to serial adapters are too slow to be useful with the ZX microcontrollers.
We have found that adapters based on the second generation FTDI chips seem to work well.
The ZBasic IDE, compiler and documentation may be obtained free of charge via the Download page. See the menu at the left.
