i am a new user for msc1211y5, i have no idea to start a DAC program.
"have using Programming language C++ before." So you should understand the basic principles of starting any program in any language for any target: 1. Define the problem 2. Design a solution 3. Implement the solution "i never do any microcontroller programming before" First, you need to read the uVision Getting Started guide, and work through the example projects in it. This will give you a proper introductions to the tools, how they work, and how to use them - rather than just jumping-in blindly at the deep-end! You need to read the following documents - commonly referred to as "the bible" for the 8051: Chapter 1 - 80C51 Family Architecture: http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_ARCH_1.pdf Chapter 2 - 80C51 Family Programmer's Guide and Instruction Set: http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_PROG_GUIDE_1.pdf Chapter 3 - 80C51 Family Hardware Description: http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_HARDWARE_1.pdf Here are some book lists: http://www.keil.com/books/8051books.asp http://www.8052.com/books.phtml For specific information about the DAC, you will need to read its Datasheet; this will tell you: A. What registers & settings you need to configure the DAC; B. How to start a conversion; C. How the DAC notifies you that the conversion is complete. If you're lucky, the Datasheet will include sample code to demonstrate this; if it doesn't, go to the manufacturer's website and look for Appliation Notes and other supporting documentation.