#################################################################

Version       : PLX 1.0 
Date          : September 2001
Documentation : As described in documents entitled 'PLX 1.0 ISA 
                Reference' and 'PLX 1.0 ISA Encoding'. These are
                available on the PLX website. 

#################################################################

Version       : PLX 1.1
Date          : February 2002
Changes       : (as compared to PLX 1.0)

  Deleted instructions : loadi.hi
                         loadi.lo
                         load for 1-byte and 2-byte subwords
                         load.update for 1-byte and 2-byte 
                           subwords

  New instructions     : cmp.pw0
                         cmp.pw1
                         loadi.z
                         loadi.k
                         loadx
                         loadx.update
                         mux.brcst for 2-byte subwords

  Other changes        : Two program flow exceptions are defined: 
                         (1) memory alignment and unaligned 
                             address trap
                         (2) illegal instruction trap

#################################################################

Version       : PLX 1.2
Date          : In development
Changes       : (as compared to PLX 1.1)

  Deleted instructions : none

  New instructions     : testbit.reg
                         cmp.4 (similar to cmp but compares only
                           the least-significant 4-bytes of 
                           source registers)
                         check
                         excheck
                         permset

  Other changes        : none

#################################################################