32bitmicro

Homebrew Cray-1A

FPGA, Xilinx,Cray

"As part two (see previous attempt) of my ongoing series in 'computational necromancy,' I've spent the last year and a half or so constructing my own 1/10-scale, binary-compatible, cycle-accurate Cray-1. This project falls purely into the "because I can!" category - I was poking around the internet one day looking for a Cray emulator and came up dry, so I decided to do something about it. Luckily, the Cray-1 hardware reference manual turned out to be useful enough that implementing most of this was pretty straightforward. The Cray-1 is one of those iconic machines that just makes you say "Now that's a super computer!" Sure, your iPhone is 10X faster, and it's completely useless to own one, but admit it . . you really want one, don't you?"

Now, let's get down to specs - What is this bad boy running? The original machine ran at a blistering 80 MHz, and could use from 256-4096 kilowords (32 megabytes!) of memory. It has 12 independent, fully-pipelined execution units, and with the help of clever programming, can peak at 3 floating-point operations per cycle. :"

Web page link

 

AN3262 - Using the over-the-air bootloader with STM32W108 devices

ST, STM32W, 802.15.4

"1 Introduction
This document describes the over-the-air bootloader provided for STM32W108 devices.
The over-the-air (OTA) bootloader is a modified version of the USART-based bootloader specified in application note AN3155 in order to deal with an 802.15.4 wireless communication channel rather than a USART cable."

PDF document link

AN10974 - LPC176x/175x 12-bit ADC design guidelines

"1. Introduction
The LPC175x/6x family is based on the ARM Cortex M3 core, and includes a 12-bit Analog-to-Digital (ADC) module with input multiplexing among eight pins, conversion rates up to 200 kHz, and multiple result registers. The 12-bit ADC can also be used with the GPDMA controller.
Designing a system with a 12-bit ADC requires more attention than the lower resolution ADC systems traditionally used in the NXP LPC family of products.
As a comparison, using a voltage reference of 3.3 V in a 10-bit ADC system, every converted value differs from the consecutive by 3.2 mV (3.3 V/1024). In the case of a 12-bit ADC, the LSB value goes down to 0.8 mV. So comparing 3.2 mV against 0.8 mV, it is apparent that noise reduction techniques will have a fundamental role in the system design, at both schematic and board layout level.
This application note provides general design guidelines that can be applied to the board layout design, as well as a reference design and a software project the user can utilize in order to test the LPC1700 12-bit ADC. Some test scenarios are also included, demonstrating the factors that can affect the conversion results.

2. Board reference design
A complete board reference design is provided with this Application Note. Customers can use this design as is, or as a starting point for their own designs.
Eagle Layout Editor Version 5.4.0 was used in this design, and the full project, including schematics, layout design and BOM, is attached with this document.
The main purpose of the board is for ADC testing; all ADC channels are available for test. Two BNC connectors, used to input external signal (or a fixed voltage from an external power supply) and two potentiometers, providing an adjustable voltage, can be connected to the analog input lines through a series of jumpers which select the input for each analog channel.
Different power supply schemes can be used with this board. Analog and Digital power domains can be supplied from a common source, as is the case when using the USB connector powered from a PC, or an external power supply providing the required 3.3 V externally. Another option is to provide separate power for each domain (Analog and Digital), and even the VREF (Voltage reference for the ADC) can be supplied from a separate power supply. A series of jumpers allow the user to select the desired configuration.
A JTAG/SWD debug port is available for both Debug and Flash programming. ISP can also be used for Flash programming though COM0 connector (selecting UART0 with the appropriate jumpers). UART1 can also be selected through jumpers. Two buttons for Reset and ISP are provided. A general purpose LED is available. All GPIO pins are available on the board."

ZIP file link