MCF5253 Reference Manual, Rev. 1
Freescale Semiconductor
8-1
Chapter 8
Bus Operation
This chapter describes bus functionality, the bus control signals, and the bus cycles provided for
data-transfer operations. Bus operation is defined for transfers initiated by the MCF5253 as a bus master
and for transfers initiated by an alternate bus master. This chapter includes descriptions of the error
conditions, bus arbitration, and the reset operation.
8.1
Bus Features
The MCF5253 bus operates using the following features:
•
24 bit address bus (24-bit for SDRAM access only 23-bit otherwise)
•
16 bit data bus
•
16 bit port size
•
Generates byte, word, longword, and line size transfers
•
Burst and burst-inhibited transfer support
•
Internal termination generation (TA)
8.2
Bus and Control Signals
Although the timing of these signals is referenced to the BCLK, it is not considered a bus signal. It is
expected that the clock will be routed as needed to meet application requirements.
summarizes
the MCF5253 bus signals. A brief description of the function of each signal follows.
NOTE
An overbar indicates an active-low signal.
Table 8-1. MCF5253 Bus Signal Summary
Signal Name
Direction
Description
A[24:1]
Out
Address bus
RW
Out
Read-write control
D[31:16]
In/Out
Data bus
CS0/CS4
Out
Chip select 0 / Chip select 4
CS1/QSPI_CS3/GPIO28
Out
Chip select 1
OE
Out
Output enable
Summary of Contents for MCF5253
Page 1: ...Document Number MCF5253RM Rev 1 08 2008 MCF5253 Reference Manual...
Page 26: ...MCF5253 Reference Manual Rev 1 xxvi Freescale Semiconductor...
Page 32: ...MCF5253 Reference Manual Rev 1 xxxii Freescale Semiconductor...
Page 46: ...MCF5253 Introduction MCF5253 Reference Manual Rev 1 1 14 Freescale Semiconductor...
Page 62: ...Signal Description MCF5253 Reference Manual Rev 1 2 16 Freescale Semiconductor...
Page 98: ...Instruction Cache MCF5253 Reference Manual Rev 1 5 10 Freescale Semiconductor...
Page 104: ...Static RAM SRAM MCF5253 Reference Manual Rev 1 6 6 Freescale Semiconductor...
Page 128: ...Synchronous DRAM Controller Module MCF5253 Reference Manual Rev 1 7 24 Freescale Semiconductor...
Page 144: ...Bus Operation MCF5253 Reference Manual Rev 1 8 16 Freescale Semiconductor...
Page 176: ...System Integration Module SIM MCF5253 Reference Manual Rev 1 9 32 Freescale Semiconductor...
Page 198: ...Analog to Digital Converter ADC MCF5253 Reference Manual Rev 1 12 6 Freescale Semiconductor...
Page 246: ...DMA Controller MCF5253 Reference Manual Rev 1 14 18 Freescale Semiconductor...
Page 282: ...UART Modules MCF5253 Reference Manual Rev 1 15 36 Freescale Semiconductor...
Page 344: ...Audio Interface Module AIM MCF5253 Reference Manual Rev 1 17 46 Freescale Semiconductor...
Page 362: ...I2 C Modules MCF5253 Reference Manual Rev 1 18 18 Freescale Semiconductor...
Page 370: ...Boot ROM MCF5253 Reference Manual Rev 1 19 8 Freescale Semiconductor...