MC68030 Datasheet, PDF (173/602 Pages) Motorola, Inc – ENHANCED 32-BIT MICROPROCESSOR

Bus Operation
UUD
UMD
LMD
LLD
UD
LD
A0
A1
SIZ0
UUD = UPPER UPPER DATA (32-BIT PORT)
UMD = UPPER MIDDLE DATA (32-BIT PORT)
LMD = LOWER MIDDLE DATA (32-BIT PORT)
SIZ1
LLD = LOWER LOWER DATA (32-BIT PORT)
UD = UPPER DATA (16-BIT PORT)
LD = LOWER DATA (16-BIT PORT)
R/W
NOTE: These select lines can be combined with the address decode circuitry or all can be generated within the same
programmed array logic unit.
Figure 7-18. Byte Data Select Generation for 16- and 32-Bit Ports
7-26
MC68030 USER’S MANUAL
MOTOROLA