Signal Descriptions; Signal Groupings - Motorola MPC533 Reference Manual

Chapter 2

Signal Descriptions

This chapter describes the MPC533 microprocessor's external signals. It contains a
description of individual signals, showing their behavior, when the signal is an input or an
output, and which signals are multiplexed with other signals.
A bar over a signal name indicates that the signal is active-low—for example, TA (transfer
acknowledge). Active-low signals are referred to as asserted (active) when they are low and
negated when they are high. Signals that are not active-low, such as ADDR[8:31] (address
bus signals) and DATA[0:31] (data bus signals) are referred to as asserted when they are
high and negated when they are low. Signals may show in different formats in the
documentation, that is, a bus might be broken into single bit signals with a "_b" and buses
might be broken into individual bit wide signals, for example DATA[0:31] might be
DATA0, DATA1, and so forth.
Refer to Appendix E, "Electrical Characteristics," for detailed electrical information for
each signal.
2.1

Signal Groupings

Figure 25-1 shows the external signals of the MPC533 grouped by functional module (pad
area).
MOTOROLA Chapter 2. Signal Descriptions 2-1
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE