Jack Ganssle 
Firmware Handbook [PDF ebook] 

The Firmware Handbook provides a comprehensive reference for firmware developers looking to increase their skills and productivity. It addresses each critical step of the development process in detail, including how to optimize hardware design for better firmware. Topics covered include real-time issues, interrupts and ISRs, memory management (including Flash memory), handling both digital and analog peripherals, communications interfacing, math subroutines, error handling, design tools, and troubleshooting and debugging. This book is not for the beginner, but rather is an in-depth, comprehensive one-volume reference that addresses all the major issues in firmware design and development, including the pertinent hardware issues.