Chapter 20. Bus Operation
20-1
Chapter 20
Bus Operation
The MCF5272 bus interface supports synchronous data transfers that can be terminated
synchronously or asynchronously and also can be burst or burst-inhibited between the
MCF5272 and other devices in the system. This chapter describes the functioning of the bus
for data-transfer operations, error conditions, bus arbitration, and reset operations. It
includes detailed timing diagrams showing signal interaction. Operation of the bus is
defined for transfers initiated by the MCF5272 as a bus master. The MCF5272 does not
support external bus masters. The MCF5272 has three on chip bus masters, the CPU, the
Ethernet controller, and the memory-to-memory DMA controller.
20.1 Features
The following list summarizes the key bus operation features:
•
23 bits of address and 32 bits of data
•
Device physical data bus width configurable for 16 or 32 bits
•
Accesses 8-, 16-, and 32-bit port sizes
•
Generates byte, word, longword, and line size transfers
•
Burst and burst-inhibited transfer support
•
Internal termination generation
20.2 Bus And Control Signals
20-1 summarizes MCF5272 bus signals described in Chapter
Table 20-1. ColdFire Bus Signal Summary
Signal Name
Description
I/O
A[22:0]
Address bus
O
BS[3:0]
Byte strobes
O
CS[7:0] Chip
selects
O
D[31:0]
Data bus
I/O
INT[6:1]
Interrupt request
I
Содержание DigitalDNA ColdFire MCF5272
Страница 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Страница 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Страница 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Страница 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Страница 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Страница 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Страница 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Страница 338: ...13 44 MCF5272 User s Manual Application Examples ...
Страница 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Страница 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Страница 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Страница 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...
Страница 548: ...INDEX Index 12 MCF5272 User s Manual ...