Well I must admit that this is one blog post I never expected to write. When I started writing the MicroZed Chronicles, I was never sure I would be writing the 52nd weekly instalment. Having achieved this milestone and more than 150,000 views along the way, I would like to look back over the year and review what I have covered on the Zynq SoC. I’ll then outline a few of my plans for the future.
The first six posts looked at the basics of the Zynq software environment we would be using. We developed software to run a simple “hello world” program and we had this program boot from our non-volatile memory of choice.
Having covered the basics of getting programs up and running on the Zynq, we then introduced I/O basics on Zynq PS (Processor Side)—parts 7 to 13—introducing the XADC and looking at the Zynq SoC’s MIO (Multiplexed I/O) block and the GIC (Generic Interrupt Controller), which then allowed us to use interrupts in our designs going forward. This short blog sequence includes the most read of all the MicroZed Chronicles posts with more than 16000 views.
Becoming familiar with Zynq SoC interrupts allowed us to look at the private timers—in blogs 14 to 20—and the watchdog timers and TTCs (Triple Timer Counters) available to the PS side of the device. We also looked at using these timers in applications.
By the time we finished looking at the Zynq TTC, we had completed our examination of the PS side of the Zynq SoC. It was time to introduce the Zynq PL (Programmable Logic) and the communication mechanisms between the Zynq PS and the PL. Between blogs 21 and 29, we explored the interface between the Zynq PL/PS, how to create our own peripherals in the Zynq PL, and how to communicate with these peripherals from the Zynq PS. These blogs also explored the overhead associated with using the PL for processing and as such introduced the concept of DMA to transfer blocks of data effectively between the PL and the two on-chip ARM Cortex-A9 MPCore processors and the peripherals within the PS side of the Zynq SoC.
The next eight blogs—30 to 37—looked in depth at how we could use what we had learned to date to create a system that’s capable of driving an Adafruit NeoPixel LED string or array under command of a remote host PC. These blogs also introduced the MicroZed I/O Carrier card and its PMOD interfaces.
Up until this point, all of the software had been bare-metal—without an operating system. However the next blog tranche looked at the basic concepts of operating systems and then introduced the Micrium µC/OS-III and FreeRTOS operating systems.
As we had until recently not been using an operating system, we had also been using just one of the two ARM Cortex-A9 processors within the Zynq. The most recent MicroZed Chronicles blogs have focused on using both of the ARM Cortex-A9 processors within the Zynq PS in an Asymmetric MultiProcessing (AMP) manner. We looked at the how we do this with the toolset and how we can communicate between processors and generate interrupts from one processor to the other.
Over the next year we will be putting Linux on the Zynq and looking at how we can profile and debug software. We’ll also look at more advanced AXI interfaces that we can use to communicate between the Zynq PL and PS. Those are a few of the topics I plan to cover in my next 52 blog posts.
However to celebrate the first 52 posts, I have collated the 51 previous instalments into a PDF download called the MicroZed chronicles, which you can download by clicking here.
Thanks for reading over this past year!
Please see the previous entries in this MicroZed series by Adam Taylor: