68020 cacr is:
00000000 00000000 00000000 0000<c><ce><f><e>
c = clear
ce = clear entry (uses caar)
f = freeze
e = enable

68030 cacr is:
00000000 00000000 00<wa><dbe><cd><ced><fd><ed> 000<ibe><ci><cei><fi><ei>
i=icache, d=dcache
[id]be = burst-mode fill enable
c[id] = clear
ce[id] = clear entry (uses caar)
f[id] = freeze
e[id] = enable
wa = write allocate
*be controls using burst-mode reads to fill cache lines on a miss
	0: fill one longword at a time
	1: burst-mode fill entire line (4 longwords)
wa controls what happens when a miss occurs on a write cycle
	0: write to memory, don't touch cache
	1: write to memory and cache