VHDL tutorial - combining clocked and sequential logic
Need the ADC clock to sometimes be the raw 40MHz input? Gene Breniman shows how to extend a reloadable, counter-based VHDL clock divider to support a master-clock pass-through by using a conditional signal assignment to switch between the internal ADCClk and Mclk. The article also covers remapping ClkSel values and includes a working XC2C32A CPLD build that leaves room for future enhancements.
Designing Embedded Systems with FPGA-2
Turning an FPGA hardware design into a running embedded system is mostly tool work. This post walks through using Xilinx EDK to compile a base design into a .bit bitstream, generate libraries and board support packages from .mhs and .mss files, and build MicroBlaze applications with GCC. It highlights the default boot placement at 0x0 and why some apps need an explicit execution transfer.
VHDL tutorial - part 2 - Testbench
In this follow-up Gene Breniman builds a VHDL testbench in Xilinx ISE, showing how to generate a continuous master clock, apply a power-on reset, and sequence register strobes to change clock divisors. He walks through timing waits and observation delays needed to verify ADC clock rates. The article also shows how simulation exposed a copy-paste bug in the original design.
Designing Embedded System with FPGA - 1
Getting an embedded system running on an FPGA is much simpler than it sounds when you use Xilinx EDK and a soft processor. Pragnesh Patel walks through a beginner-friendly approach using the MicroBlaze CPU, drag-and-drop IP cores, and a Spartan-3E starter kit so you can assemble peripherals without deep VHDL knowledge. The post focuses on the EDK base system builder and first setup steps to generate a working design.
Layout recomendations and tips for best performance against EMC
Good PCB layout will prevent many EMC headaches before you even power the board. Maykel Alonso offers a practical checklist covering component and feed analysis, package and PCB choices, placement, routing, and via rules. The post focuses on concrete, low-effort measures like preferring SMD parts, using a 4-layer FR-4 stack with dedicated ground and power planes, and keeping return paths tight to cut emissions and susceptibility.
Tracing code and checking timings
When you cannot afford logs or to stop the CPU, GPIO toggles become a powerful real-time tracer. Richard shows how driving IO pins and watching them with an oscilloscope or logic analyzer reveals control flow, function timings, and ISR activity with very little overhead. He also explains using direct port writes and conditional compilation to keep measurements noninvasive and easy to enable or disable.
Good old multiplexed keypad in an embedded system
Multiplexed keypads remain the most practical input for mid-budget embedded projects, especially where hard-wired keys survive harsh environments and rough usage. Jayaraman lays out a simple, reusable approach by splitting key handling into three tiny modules: a GlanceKey quick check, on-demand Decode, and a compact state machine. The pattern cuts CPU time, runs from a timer, and boosts portability across MCUs.
Kind of Buggy! The state machine fantastic//
Richard Dorfner shows a compact way to debug an intermittent homing failure in a Pan/Tilt camera by logging the last 30 state transitions in a circular buffer. He tags each entry with a function identifier and uses breakpoints to walk the recorded sequence backwards. That reveals a timing interaction between a 100 ms periodic flag and the homing code that stopped the motor state machine. The method is low-overhead and ideal for single-threaded embedded systems.
Hidden Gems from the Embedded Online Conference Archives - Part 1
Discussion of a "hidden gem" from the Embedded Online Conference archives!
Tracing code and checking timings
When you cannot afford logs or to stop the CPU, GPIO toggles become a powerful real-time tracer. Richard shows how driving IO pins and watching them with an oscilloscope or logic analyzer reveals control flow, function timings, and ISR activity with very little overhead. He also explains using direct port writes and conditional compilation to keep measurements noninvasive and easy to enable or disable.
Layout recomendations and tips for best performance against EMC
Good PCB layout will prevent many EMC headaches before you even power the board. Maykel Alonso offers a practical checklist covering component and feed analysis, package and PCB choices, placement, routing, and via rules. The post focuses on concrete, low-effort measures like preferring SMD parts, using a 4-layer FR-4 stack with dedicated ground and power planes, and keeping return paths tight to cut emissions and susceptibility.
Intro to Microcontrollers Part 2: AVR Microcontrollers
This follow-up explores getting an AVR Dragon working with an ATtiny24A, covering the necessary cables, BOM choices, and Atmel Studio setup. It walks through firmware updates, an ADC-based internal temperature sensor example using reduced-noise ADC and ISR handling, and practical debugging tips including debugWire versus ISP and high-voltage recovery. Expect candid hardware caveats like weak drive strength and 5V power quirks.
