The 68030 features an on_chip split instruction and data cache of 256 bytes each. It also has an on-chip memory management unit. The 68881 and the faster 68882FPU (floating point unit) chips could be used with the 68030. A lower cost version of the 68030, the Motorola 68EC030, was also released, lacking the on-chip MMU.
As a microarchitecture, the 68030 is uninteresting. It is little more than a 68020 core with an added data cache (which made little difference to performance) and a process shrink. Motorola used the process shrink to allow them to pack more hardware on the die. In this case it was the MMU, a 68851 compatible. Per clock, however, the 68030 did not differentiate itself in performance from the 68020 that it was derived from. The finer manufacturing process, however, allowed Motorola to scale the processor to 50MHz. The EC variety topped out at 40MHz.