RTC, DS1340

Interface: I2C
Device address: 0b1101000x
SPEC裡說明讀取的部份不是很清楚，
Start == Read Command == Data == ... == Stop
Command: Device address + Read bit.
照著上列順序並沒辦法讀到資料。

在讀取資料前必須先以Write command將欲讀取的位址寫入才可。
Start == Write Command == Data Address

完整的讀取順序：
Start == Write Command == Data Address == Re-Start == Read Command == Data == ... == Stop

Code Reference

Ubuntu

Ubuntu Home Page | Ubuntu: "What is Ubuntu?

Ubuntu is a community developed, linux-based operating system that is perfect for laptops, desktops and servers. It contains all the applications you need - a web browser, presentation, document and spreadsheet software, instant messaging and much more."

Cortex-M3

Cortex-M3, cost down的ARM7TDMI
但是在Cortex-M3 和 ART7TDMI的比較發現到雖然Cost Down, 可是功能卻比ARM7TDMI優。不論是code size, cost, die footprint, power consumption, performance, 而且還多了一個Nested Vectored Interrupt Controller.

ARM Cortex-A Series: Applications processors for complex OS and user applications
ARM Cortex-R Series: Embedded processors for real-time systems
ARM Cortex-M Series: Deeply embedded processors optimized for microcontroller and low-cost applications

ARM Purchases Keil Software

ARM把Keil買下來了哦！
http://www.microcontroller.com/news/arm_keil.asp

As the MCU applications shift from 8/16-bit to 32-bit solutions, the combination of the ARM Cortex processor, which was specifically designed for microcontroller applications, our RealView high-performance compiler, and Keil's complementary MCU tools for ARM, will enable new generations of ARM MCU solutions.
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原來ARM Cortex-M3 processor 是專為MCU應用所設計的！

Decision

看來老闆還是蠻喜歡用ST的, 可能是他們的價錢好談。
但不知道會不會像Microchip一樣program時還注意一些奇奇怪怪的問題。