ken@turtlevax.UUCP (Ken Turkowski) (04/07/86)
In article <208@valid.UUCP> gelfand@valid.UUCP (Brooks Gelfand) writes: >The Motorola 68010 has a loop mode operation that works with the >DBcc instruction. In this case the loop is only one instruction deep. There are even further restrictions; you can do a block copy L: movl a0@+,a1@+ dbra d7,L but you can't poll an I/O device's busy bit M: btst #3,a0@ dbeq d7,M and still remain within the cache. Does anybody know why Motorola doesn't allow just any instruction that will fit? -- Ken Turkowski @ CIMLINC, Menlo Park, CA UUCP: {amd,decwrl,hplabs,seismo}!turtlevax!ken ARPA: turtlevax!ken@DECWRL.DEC.COM