Motorola MC68030 - Page 173

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