CACHE-DUMP FUNCTIONS IN M-BOX

SMA BITS 33,34,35

    BIT 33  IF ON, STANDARDIZE USE BITS EACH CYCLE
    BITS 34,35:
       =0  →→  NO-OP
       =1  →→  INIT CACHE-DUMP COUNTER ETC.
       =2  →→  CACHE-DUMP (STORE IN MEM IF NEEDWRITE)
       =3  →→  INVALIDATE CACHE (CLEAR IT, DON'T STORE)

           SO, TO GET CERTAIN EFFECTS:
              TO CLEAR ENTIRE CACHE, AND STANDARDIZE USE BITS (LIKE AT POWER-UP)
                  DO 1 C-D CYCLE WITH SMA 33-35 =1 (INIT) THEN REPEATED CYCLES
                  WITH SMA 33-35 =7 (STANDARDIZE USE BITS, AND INVALIDATE) UNTIL
                  C-D DONE SIGNAL.
              TO DUMP CACHE INTO CORE, DO 1 C-D CYCLE WITH SMA 33-35 =1 (INIT)
                  THEN REPEATED C-D CYCLES WITH SMA 33-35 =2 (OR 6 IF YOU WANT
                  TO STANDARDIZE USE BITS) UNTIL C-D DONE SIGNAL
               [IN THESE CASES SMA 29 SHOULD BE 0]

SMA BITS 29-32:
    BIT 29 ENABLES THESE FUNCTIONS
    BITS 30,31,32:
       =0  →→  NO-OP
       =1  →→  LOAD MAP POINTERS:
                   ADDRESS FROM SMA 23-26 (SEE BELOW FOR MEANING OF REGISTERS)
                   DATA FROM SM. ADDRESS LOADED INTO POINTER FROM SM 11-33 IN
                                              STANDARD ADDRESS FORMAT.
                                     SIZE LOADED FROM SM 0-10 FOR USER AND XUSER.
       =2  →→  NO-OP
       =3  →→  SET AND CLEAR ACCESSED & WRITTEN BITS
                  ADDRESS IS OUTPUT OF MAP!  SO ACCESSED AND WRITTEN BITS INVOLVED
                            ARE FOR MAPPED VERSION OF ADDRESS IN SMA. (MAP ENTRY
                            MUST BE PRESENT.  IF IN DOUBT, USE ABSOLUTE ADDRESS
                            (SEE ADDRESS FORMAT BELOW) IN WHICH CASE SMA GOES
                            STRAIGHT THROUGH).
                  DATA IS SM 34,35:  34 = 0 CLEAR WRITTEN
                                     34 = 1 SET WRITTEN
                                     35 = 0 CLEAR ACCESSED
                                     35 = 1 SET ACCESSED
       =4  →→  CLEAR SELECTED 4-WAY VALID BITS:
                  ADDRESS IS SMA 11-26 IN STANDARD FORMAT, EXCEPT THAT ALL BUT
                            12(USER/EXEC) 18 AND 19 ARE IGNORED.(TAKES 8 CYCLES
                            TO CLEAR WHOLE THING.)
                  DATA IS SM 4-35. CLEARS VALID BITS FOR WHICH SM BIT IS OFF.
                            LEAVES OTHERS ALONE. SM 4 CORRESPONDS TO ADDRESS
                            WITH SMA 20-24 =0. SM 35 CORRESPONDS TO ADDRESS WITH
                            SMA 20-35 =1.
       =5  →→  CLEAR 1 PAGE VALID BIT:
                 ADDRESS IS SMA 11-26 IN STANDARD FORMAT (CLEARS FOR USER, EXEC, OR
                                                     XUSER. FOR ABSOLUTE, IS NO-OP.)
                 NO DATA.
       =6  →→  LOAD AC POINTER A.
                 NO ADDRESS.
                 DATA IS SM 11-31, AND IS LOADED INTO ACPA 11-31.
       =7  →→  LOAD AC POINTER B.
                 NO ADDRESS.
                 DATA IS SM 11-31, AND IS LOADED INTO ACPB 11-31.


                       ACCESSED AND WRITTEN BITS TIMING:

                 BITS ARE AVAILABLE FROM ABOUT TIME 110 TO 133. THAT IS TO
                 SAY, SINCE THE ADDRESS INPUTS (TO 74200'S) ARE FROM THE
                 OUTPUT OF THE MAP, THROUGH SEVERAL LEVELS OF LOGIC, THE
                 BITS ARE AVAILABLE FROM JUST BEFORE THE A1 TIME FOLLOWING
                 THE CYCLE TO THE START OF B0.  THEY MAY BE STROBED INTO A
                 TYPE D FLIP FLOP WITH B CLOCK.


                        STANDARD ADDRESS FORMAT:

     BITS 11,12:
            INDICATE USER/EXEC ETC. AS:
                =0  USER      (13 TO 35 ARE 23 BIT VIRTUAL ADDRESS)
                =1  EXEC      (18 TO 35 ARE 18 BIT VIRTUAL ADDRESS)
                =2  XUSER     (13 TO 35 ARE 23 BIT VIRTUAL ADDRESS)
                =3  ABSOLUTE  (14 TO 35 ARE 22 BIT ABSOLUTE ADDRESS)
     BITS 13-17:
            COMPARED ASSOCIATIVELY FOR USER & XUSER, IGNORED FOR EXEC,
                        HIGH ORDER BITS OF ABSOLUTE (13 IGNORED).
     BITS 18-26:
            ADDRESS INTO MAP MEM FOR EXEC AND USER, COMPARED ASSOCIATIVELY
                        FOR XUSER, PART OF ADDRESS FOR ABSOLUTE.
     BITS 27-35:
            ADDRESS INTO CACHE.


                        USES OF MAP POINTERS

            0-3  EXEC:   0  FOR  000000 TO 177777
                         1  FOR  200000 TO 577777
                         2  FOR  600000 TO 637777
                         3  FOR  640000 TO 777777

            4    USER
            5    XUSER
            6    SHARED
            7    INDIRECT
            10 TO 17 HAVE NO ASSIGNED USE. MAY BE USED WITH THE "IMMEDIATE"
                    MODE OF INDIRECT.