Embedded Controller Hardware Design targets one of the most popular embedded controllers around, the 8051. The book, written by Ken Arnold for LLH Technology Publishing, is a great introduction to low-end, controller design, especially for developers fresh out of college or just off other projects that are used to 32-bit systems running Windows and Linux. Experienced 8-bit embedded designers will not find the book as useful unless they're unfamiliar with the 8051 and need to use it in a new project.
The coverage ranges from a novice level introduction of electronics that touches on resistors and tristate buffers to more advanced topics like bus current limitations and using 8-bit microcontrollers and PLDs (programmable logic devices). The bulk of the book concentrates on important detail like bus loading, timing, and the use of I/O, DMA, and interrupts.