The W78E58B is an 8-bit microcontroller which has an in-system programmable Flash EPROM for
firmware updating. The instruction set of the W78E58B is fully compatible with the standard 8052. The
W78E58B contains a 32K bytes of main ROM and a 4K bytes of auxiliary ROM which allows the
contents of the 32KB main ROM to be updated by the loader program located at the 4KB auxiliary
ROM 512 bytes of on-chip RAM four 8-bit bi-directional and bit-addressable I/O ports an additional 4-
bit port P4 three 16-bit timer/counters a serial port. These peripherals are supported by a eight
sources two-level interrupt capability. To facilitate programming and verification, the ROM inside the
W78E58B allows the program memory to be programmed and read electronically. Once the code is
confirmed, the user can protect the code for security
The idea for this book was born during one of my project-related trips to the beautiful city
of Hangzhou in China, where in the role of Chief Architect I had to guide a team of very
young, very smart and extremely dedicated software developers and verification engineers.
Soon it became clear that as eager as the team was to jump into the coding, it did not have
any experience in system architecture and design and if I did not want to spend all my time in
constant travel between San Francisco and Hangzhou, the only option was to groom a number
of local junior architects. Logically, one of the first questions being asked by these carefully
selected future architects was whether I could recommend a book or other learning material
that could speed up the learning cycle. I could not. Of course, there were many books on
various related topics, but many of them were too old and most of the updated information
was either somewhere on the Internet dispersed between many sites and online magazines, or
buried in my brain along with many years of experience of system architecture.
Multiple-voltage electronics systems often requirecomplex supply voltage tracking or sequencing, whichif not met, can result in system faults or even permanentfailures in the fi eld. The design diffi culties in meetingthese requirements are often compounded in distributedpowerarchitectures where point-of-load (POL) DC/DCconverters or linear regulators are scattered across PCboard space, sometimes on different board planes. Theproblem is that power supply circuitry is often the lastcircuitry to be designed into the board, and it must beshoehorned into whatever little board real estate is left.Often, a simple, drop-in, fl exible solution is needed tomeet these requirements.
