SX Chip General Information
Parallax SX chips are 8-bit, high-speed microcontrollers with flash program memory, and in-system programming and debugging capability. Choose the SX for your design if you need:
- Speed - operating frequencies up to 75 MH
- A pipelined instruction set - non-branching commands execute in a single cycle
- Jitter-free 3-cycle internal interrupt response
- Flexible I/O, with selectable internal pull-ups and TTL or CMOS logic level
- Schmitt-trigger or analog comparator support on select ports
- Outputs capable of sourcing/sinking 30 mA
- A built-in 8-bit real-time clock, watchdog timer, and brown-out detector
- Multi-input wakeup logic on 8 pins
- An internal RC oscillator configurable from 31.25 kHz to 4 MHz
- RoHS compliance
- Free programming software for Assembly and SX/B (BASIC)
- Generous production-quantity price breaks
Parallax is the only worldwide supplier of the SX chip. The key details for each SX chip are listed below. Click on the appropriate part number for complete details, including pricing information and data sheets. If you require additional information, email us at sales@parallax.com.
| SX Chip Overview |
| Part # |
Pins |
I/O |
EE/Flash |
RAM |
Rail/Tray QTY |
| SX20AC/SS-G |
20 |
12 |
2K bytes |
137 bytes |
67 per rai |
| SX28AC/DP-G |
28 |
20 |
2k bytes |
136 bytes |
16 per rail |
| SX28AC/SS-G |
28 |
20 |
2k bytes |
136 bytes |
48 per rail |
| SX48BD-G |
48 |
36 |
4k x 12 words |
262 bytes |
250 per tray |
Note: All SX chips we currently stock are RoHS (Restriction of Hazardous Substances) Compliant.
The SX-Key USB is Parallax’s primary development tool for the SX line of microcontrollers. Used with the SX-Key USB software, this tool can program SX chips in-system and perform in-circuit source-level debugging. The 4-pin socket connects to the programming header on our SX development boards. USB-powered.
SX-Key Editor Software
This free software package is an integrated development environment for the SX line of microcontrollers, supporting every chip in production. Used in conjunction with the SX-Key or SX-Blitz programming tools, the user can write code, assemble/compile it, and download to the SX chip. The SX-Key USB also enables in-circuit source-level debugging, allowing the user to step through the code line-by-line or stop at set breakpoints.
Also at the user’s fingertips is an on-board programmable clock. The frequency output of this clock is adjusted from the software IDE with a slider bar between 4 and 100 MHz.
The SX-Key Editor Software is compatible with Windows 98/NT/2K/XP/Vista platforms. Obtain the latest version free from the SX Software and Documentation Downloads page.
SX/B Compiler
SX/B is a BASIC compiler designed for the Parallax SX family of microcontrollers, with two specific goals in mind:
- Expedite the task of the professional engineer by creating a simple, yet robust high-level language for the SX microcontroller. This allows SX-based projects to be prototyped and coded quickly.
- Assist the student programmer wishing to make the transition from pure high-level programming (i.e. BASIC Stamp) to low-level programming (SX assembly language).
The SX/B compiler is built right into the free SX-Key IDE software and supports the entire series of SX chips. BASIC keywords are highlighted automatically within the editor. The help file has a comprehensive list of all of the SX/B commands and many examples of their use. Interfacing with other devices is easy because SX/B has high-level commands for Serial, SPI, I2C, and 1-Wire.
With SX/B, interrupts have never been easier. Creating a periodic interrupt every millisecond is as simple as “INTERRUPT 1000” with no restriction on what commands can be used with an interrupt routine. Read more about the SX/B Compiler here.