- Category: Kinetis
The Bare Metal Enthusiast: Winding the Clock
Excellent overview of the internal clock generation in modern MCUs using Frequency Multiplication.
"For those of us old enough to remember, a clock or watch had to be wound before it would start working. You also had to set the time. Before anything works properly in a microcontroller unit (MCU), we first need to configure its clock. As you can imagine, this is a little more complicated than spinning a knob on a watch: It involves specifying where the clock gets its source signal from (which is somewhat akin to winding it), and what output frequency it generates to drive the MCU and its peripherals (similar to setting its time)."
"Lots of Clocking Options
Now let’s take a look at something a little more complex. Figure 4 is a block diagram of the Multipurpose Clock Generator (MCG) within Freescale’s 32-bit ARM Cortex-M4 Kinetis Family of MCUs. This specific diagram applies to the most recent 100MHz versions of the K10, K20 and K60 MCUs."
- Category: Hacking
Camera Pi – DSLR Camera with Embedded Computer
"I’ve had the idea of embedding a computer DSLR camera for a couple of years now, but for whatever reason I never got around to implementing it, mostly due to the cost of small single board computers. Until now, that is. With the release of the Raspberry Pi, embedded computing has all of a sudden become much more affordable. At €35 for the computer, it’s far cheaper than any of it’s rivals."
- Category: UART
Using Port Powered Converters
"When using or installing any RS-232 port powered device, it is important to keep a few things in mind. The two main considerations are the power available from the RS-232 port and the power dissipated by the RS-422 or RS-485 system.
Power Dissipation
- The power dissipated when using a port-powered converter is consumed by:
- The cable on the RS-232 side of the converter.
- Termination resistors used on the RS-422 or RS-485 transmission line.
- The RS-422 or RS-485 cable.
- The port powered converter."
- Category: Holtek
Holtek launches enhanced ARM Cortex-M3 based Microcontrollers
"The HT32F1755/1765/2755 series devices contain 128K bytes of Flash Program Memory and 32K~64K bytes of SRAM Data Memory together with a newly designed 12-channel PDMA for higher efficiency applications. The integrated Timer Module can implement functions such as Timer/Counter, Capture, Compare, Single Pulse Output, PWM modes and also provide QEI, Hall Sensor interface features and special complementary PWM outputs. Together with an 8-channel 12-bit 1Msps high speed A/D converter, these new devices can meet the requirements of three-phase motor control applications. With regard to the HT32F2755 device, Holtek provides an additional high-speed CMOS sensor camera interface with the frame rate up to 30 frames/s for QVGA(320x240) format."
- Category: ARM
Xen on ARM with virtualisation extensions progress
"Thanks to some recent work, mainly by Stefano Stabellini, we are now able to start our first guest domain, including paravirtual console disk and network devices!
The main implementation work here has been to implement support for the core pieces of infrastructure will underpins the PV drivers, primarily that is event channels and grant tables all of which Stefano has implemented recently. One of our key design goals with this port of Xen was to make good use of the hardware virtualisation extensions, and at the same time implement paravirtualisation where it offers obvious benefits. For example we wanted to use paravirtualised device drivers for I/O as they provide significant performance benefits compared to emulated devices."
- Category: ARM
Oracle Java Update Shows Future For ARM
"While only an “update” for the Java community, this release is a significant milestone not only for Calxeda, but the entire ARM ecosystem. Java SE 7 Update 6 now introduces a general-purpose port of the JDK to Linux ARM. "
Oracle releases JDK for Linux ARM, JRE for Mac OS X - blog page link
"With JDK 7u6 we are also adding a general-purpose port of the JDK (but not a desktop JRE) to Linux ARM, and making it available under the same licensing terms as Oracle Java for other platforms. This JDK release is aimed at the emerging ARM server market, and for the community working on development boards such as the BeagleBoard, PandaBoard and the Raspberry Pi. This port provides 32-bit binary for ARMv6 and v7, with full support for Swing/AWT, both client (C1) and server (C2) compilers and runs on most Linux distributions. One caveat is that the current binary is softfloat ABI only, so it won't work with (for example) the Raspbian distribution which uses the hardfloat ABI. We are planning to add hardfloat support in an upcoming JDK release, as well as support for JavaFX on ARM."
Oracle Press Release - web page link
- Category: Digital Electronics
E2.1 Digital Electronics 2 course
Covers Verilog, FPGA, Altera
"Aims & Objectives
The aims of the course are:
- To enable you to analyse and synthesize small synchronous digital systems.
- To give an understanding of factors that limit the performance of digital systems.
- To give an understanding of how digital systems communicate with each other and with their external environment.
By the end of the course, you should be able to:
- analyse the operation of synchronous digital systems
- synthesize a synchronous digital system to meet a specification
- determine the worst-case propagation delay of a combinational circuit
- evaluate the performance of A/D and D/A conversion circuits
- design arithmetic circuits to meet a specification and determine the propagation delay
- design some digital circuits on real hardware"
- Category: Marvell
Marvell co-founder: Combo chips are the future
"Integrating mobile processors with modems is a burgeoning trend, and according to Marvell co-founder, Weili Dai, it’s the future.
“Building a single unified platform to address global needs through the combination of modem and application processor is very important for that ‘always on, always connected’ lifestyle, especially when it comes to tablets,” said Dai.
Marvell just announced its new PXA988 and PXA986 products, chips that include everything but the kitchen sink in terms of connectivity, from Wi-Fi to Bluetooth to FM radio, Near Field Communications (NFC) and GPS. "
- Category: Cortex-A
Cortex-A Series Programmer’s Guide - Version 3
Updated with preliminary information on ARM big.LITTLE concept or Heterogeneous Multiprocessing (HMP).
Covers Cortex-A5, Cortex-A7, Cortex-A8, Cortex-A9 and Cortex-A15.
This document is only available to registered ARM customers.