Specifications

7-1
7
Chapter 7Power Hawk 620/640 Hardware Environment
7
7
7
The objective of this chapter is to give some background information to address hardware
issues involved in developing a device driver for the Power Hawk 620/640 computer
systems. This chapter helps understand the effect that hardware configuration has on I/O
function and performance.
Some hardware issues are general in nature—for example, I/O error handling (power
failure, alignment errors, controller errors, bus hangs, and so on). Other issues can be
classified according to the type of processor interfacing technique used to communicate
with the device—that is programmed I/O, interrupts, direct memory access (DMA). There
are such issues as addressing, byte ordering and alignment, word sizes, and the
configuration of arbitration levels and the assignment of arbitration priorities. When
communicating with devices via interrupts, there are issues such as whether the interrupt
levels can be shared and configured to ensure adequate performance levels. Finally, other
issues arise when communicating with devices via DMA—for example, cache coherency,
buffering and addressing.
The first part of this chapter gives a brief overview of the main architectural features of the
platforms in terms of its system and I/O architecture: processors, memory and I/O
expansion and configuration, etc.
The second part examines hardware issues one by one including the physical addressing
on the platforms, I/O bus timeout, configuration of I/O interrupt request levels and
associated priorities, and the assignment of interrupt vectors.
System Overview 7
The Power Hawk 620 systems are uniprocessor, real-time, super-microcomputers. They
are based on the Symmetric Superscalar
TM
Reduced Instruction Set Computer (RISC)
microprocessor from IBM/Motorola, the PowerPC 604e. The processor board is the
Motorola MVME 2604 Single Board Computer (SBC).
Figure 7-1 reviews some of the main elements of the Power Hawk 620 processor board.
The Power Hawk 640 systems are uniprocessor or dual processor, real-time, super-micro-
computers. They are also based on the Symmetric Superscalar
TM
Reduced Instruction Set
Computer (RISC) microprocessor from IBM/Motorola, the PowerPC 604e. The processor
board is the Motorola MVME 4604 Single Board Computer (SBC).
Figure 7-2 reviews some of the main elements of the Power Hawk 640 system.