Microcontroller User's Manual

MOTOROLA Chapter 13. External Interface Module (EIM) 13-1
Chapter 13
External Interface Module (EIM)
This chapter describes data-transfer operations, error conditions, and reset operations.
Chapter 15, “Synchronous DRAM Controller Module,” describes DRAM cycles.
NOTE:
Unless otherwise noted, in this chapter, “clock” refers to the
CLKOUT used for the bus.
13.1 Features
The following list summarizes bus operation features:
• Up to 24 bits of address and 32 bits of data
• Access 8-, 16-, and 32-bit data port sizes
• Generates byte, word, longword, and line-size transfers
• Burst and burst-inhibited transfer support
• Optional internal termination for external bus cycles
13.2 Bus and Control Signals
Table 13-1 summarizes MCF5282 bus signals described in Chapter 14, “Signal
Descriptions.”
Table 13-1. ColdFire Bus Signal Summary
Signal Name Description I/O CLKOUT Edge
A[23:0] Address bus O Rising
BS
1
Byte selects O Falling
CS[6:0]
1
Chip selects O Falling
D[31:0] Data bus I/O Rising
OE
1
Output enable O Falling
R/W
Read/write O Rising
SIZ[1:0] Transfer size O Rising