Microcontroller User's Manual

MOTOROLA Chapter 14. Signal Descriptions 14-3
Overview
Table 14-1 lists the MCF5282 signals grouped by functionality.
NOTE:
The primary functionality of a pin is not necessarily its default
functionality. Pins that are muxed with GPIO will default to
their GPIO functionality.
Table 14-1. MCF5282 Signal Description
Signal Name Abbreviation Function I/O Page
External Memory Interface
Address A[23:0] Define the address of external byte,
word, longword, and 16-byte burst
accesses.
I/O 14-18
Data D[31:0] Data bus. Provide the general
purpose data path between the MCU
and all other devices.
I/O 14-18
Byte strobes BS
[3:0] Define the byte lane of data on the
data bus.
I/O 14-19
Output enable OE
Indicates when an external device can
drive data on the bus.
O 14-19
Transfer acknowledge TA Indicates that the external data
transfer is complete and should be
asserted for one clock.
I 14-19
Transfer error
acknowledge
TEA
Indicates that an error condition exists
for the bus transfer.
I 14-19
Read/Write R/W Indicates the direction of the data
transfer on the bus.
I/O 14-19
Transfer size SIZ[1:0] Specify the data access size of the
current external bus reference.
O 14-19
Transfer start TS
Asserted during the first CLKOUT
cycle of a transfer when address and
attributes are valid.
O 14-20
Transfer in progress TIP
Asserted to indicate that a bus
transfer is in progress. Negated during
idle bus cycles.
O 14-20
Chip selects CS
[6:0] Programmed for a base address
location and for masking addresses,
port size and burst capability
indication, wait state generation, and
internal/external termination.
O 14-20
SDRAM Controller Signals
SDRAM row
address strobe
SRAS
SDRAM synchronous row address
strobe.
O 14-21
SDRAM column
address strobe
SCAS
SDRAM synchronous column address
strobe.
O 14-21