From 9af28e44ad2f5c89f290f78a17a4b521dc1001c8 Mon Sep 17 00:00:00 2001 From: Kevin Townsend Date: Sat, 5 May 2012 12:41:32 +0200 Subject: [PATCH] Added more info --- Readme.md | 125 +++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 96 insertions(+), 29 deletions(-) diff --git a/Readme.md b/Readme.md index e198551..459b1d1 100644 --- a/Readme.md +++ b/Readme.md @@ -1,14 +1,67 @@ # LPC1343 Code Base +## Overview + This software library is based on the freely available LPC1343 Reference -Design available at http://www.microBuilder.eu. Unless otherwise stated, -all files are licensed under the BSD license (see license.txt for details). +Design from http://www.microBuilder.eu, and is based around the **ARM Cortex M3 +LPC1343** from NXP. + +The LPC1343 is a modern, entry level 32-bit ARM Cortex M3 processor with +**32KB flash, 8KB SRAM**, and can be run at up to **72MHz**. It also includes +full-speed USB 2.0, along with all the main peripherals you'd expect to find +(I2C, SPI, PWM, ADC, UART, etc.). + +The LPC1000 family from NXP contains a wide variety of ARM Cortex M0 and +Cortex M3 cores, but the LPC1343 is particularly attractive in situations +where price is an issue, but a decent amount of performance is needed. It has +an efficient instruction set (most commands execute in a single clock cycle, +including single-cycle multiply, etc.), and excellent code-density thanks to +the Thumb-2 instruction set, meaning 32KB stretches a lot further than it +did with the older ARM7 or ARM9 cores even in Thumb mode. + +The ARM Cortex M0 based LPC1114 is cheaper (ridiculously cheap!), and represents +one of the best values out there when both price and power consumption are an issue, +but the Cortex M0 has a minor performance bottleneck compared to the Cortex M3 that +may or may not be important to you: The smaller, lighter-weight M0 LPC1114 is based +on a Von Nuemann architecture with a single pipeline for both instructions and +data. This means that it usually takes two clock cycles to do something on the M0 that can +be done in one clock cycle on the ARM Cortex M3 LPC1343. The M3 LPC1343 implements +a Harvard architecture with a three-stage pipeline, meaning seperate pipelines for +instructions, data and peripherals that can all be filled in the same clock cycle. + +This means that in certain situations 72MHz on the M3 LPC1343 can +actually be more than twice as fast as the 50MHz LPC1114, though this comes at the +expense of a larger and more complicated core that consumes more power and requires a +slightly larger die due to the increased gate count. + +> **M0 Sidenote:** The single-pipeline bottleneck on the M0 is addressed in the recently announced +ARM Cortex M0+, which will contain a dual pipeline, while still maintaining a very +light-weight, efficient and inexpensive core. This is probably the most important +change in the M0+ since it offers much better performance per clock cycle, meaning +you can switch back to a low-power sleep mode that much quicker for better battery life. + +If you need to get the best possible performance for your money and are doing +computationally intensive tasks or maybe a lot of rapid memory access and pin state +reads/writes, etc., the LPC1343 will be a better fit. If you need to get the lowest +possible cost and power consumption, the LPC1114 is probably the better choice, though +the LPC1343 has reasonably good power numbers as well. + +One of the biggest advantages of the LPC1343 and LPC1114, though, is that they are +99% register compatible with each other if you want or need to switch to one +or the other, and learning one makes using the other trivial. While the LPC1343 Code +Base tends to be slightly more actively maintained, there is a parallel LPC1114 Code +Base that mirrors the LPC1343 library here, and it should be painless to switch between +the two. For more information see: https://github.com/microbuilder/LPC1114CodeBase + +## License + +Unless otherwise stated, all files are generally licensed +under a modified **BSD license** (see license.txt for details). ## Downloads -The latest version of the software is always available on github at: - -https://github.com/microbuilder/LPC1343CodeBase +The latest development version of the software is always available on github at: +>https://github.com/microbuilder/LPC1343CodeBase ## Development Status @@ -20,30 +73,30 @@ and may have been abandoned once the basic features were working (setting pixels on a display, etc.), but they should serve as a good starting point for a wide variety of peripherals. -## How Can Someone Support This Project - -A lot of the recent development in this library was done -thanks to the financial support of Adafruit Industries (paying -me a salary to keep providing this stuff). If you find this library -useful, please consider ordering something from the people that -make this financially possible: http://www.adafruit.com +The code base is definately imperfect, and some growing pains and faulty early +assumptions are evident throughout, but it hopefully at least +partially fulfills the goal of providing a genuinely open source +code base for the LPC1343 and GCC with no dependencies on any one +commercial toolchain or IDE. -## Toolchains +## Supported Toolchains/IDEs -The entire LPC1343 Code Base is based around GCC, and can be built -from the command-line using only free tools like the Yagarto -distribution for Windows or the Mac, etc. +The entire LPC1343 Code Base is based around **GCC**, and can be built +from the command-line using only free tools like the **Yagarto** +distribution for Windows or the Mac, or using GCC on Linux, etc. +> http://www.yagarto.de/ -Nonetheless, it's often more productive to develop in an IDE with a +Nonetheless, it's sometimes more productive to develop in an IDE with a full set of debugging tools at your disposal, and the code base also -includes project files for Rowley Associate's Crossworks for ARM, as -well as project files for the free and open source CodeLite, which can +includes project files for Rowley Associate's **Crossworks for ARM**, as +well as project files for the free and open source **CodeLite**, which can be used in combination with a Segger J-Link for ARM and GDB Server. +Project files for these two IDEs are stored in the /build folder. -Project files for the two IDEs are stored in the /build folder, and -project files for the free LPCXpresso IDE are stored in root (see -http://www.microbuilder.eu/Projects/LPC1343ReferenceDesign/DebuggingWithLPCXpresso.aspx -for more information on using LPCXpresso). +Project files for the free (but commercial) **LPCXpresso** IDE are stored in the +root folder, and this probably represents the cheapest means to do real step-through +HW debugging. For more information on using LPCXpresso with the LPC1343 Code Base see: +>http://www.microbuilder.eu/Projects/LPC1343ReferenceDesign/DebuggingWithLPCXpresso.aspx ## Documentation @@ -53,11 +106,25 @@ inconsistencies are present since parts of the library have been reorganized working towards a 1.0.0 release. The graphics library in particular has been reorganized quite a bit. -General API Documentation: -http://www.microbuilder.eu/Projects/LPC1343ReferenceDesign/CodeBaseDocumentation.aspx +**General API Documentation:** +>http://www.microbuilder.eu/Projects/LPC1343ReferenceDesign/CodeBaseDocumentation.aspx -TFT/OLED Graphics Sub-System: -http://www.microbuilder.eu/Projects/LPC1343ReferenceDesign/TFTLCDAPI_v1_1_0.aspx +**TFT/OLED Graphics Sub-System:** +>http://www.microbuilder.eu/Projects/LPC1343ReferenceDesign/TFTLCDAPI_v1_1_0.aspx + +**Other tutorials and links:** +>http://www.microbuilder.eu/Projects/LPC1343ReferenceDesign.aspx + +## How Can Someone Support This Project? + +A lot of the recent development in this library was done +thanks to the financial support of **Adafruit Industries** (paying +my salary to keep working on this stuff!). If you find this library +useful, please consider ordering something from the people that +make this financially possible: http://www.adafruit.com -Other tutorials and links: -http://www.microbuilder.eu/Projects/LPC1343ReferenceDesign.aspx +Any additions, suggestions or bug fixes are always welcome, and this +is in fact one of the main incentives behind making this library +open source. If you have anything to contribute, using the feedback +mechanisms on Github is probably the best and most orderly way to +do this. -- 2.20.1