# 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
(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
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.
projects / hackover2013-badge-firmware.git / blobdiff