HP 3562A Service Manual page 280

MOD E L 3562A
5 . The FPP fetches a 3 2 bit co m m and u s i n g the Y bus a n d correspon d i ng global b u s
registers.
6 . The A L U s read and store the ad d ress of the data b l ock to be ope rated on.
7 . T h e instruction mapping PROM i nte rp rets the com mand data on the Y b u s a n d te l ls
the seq ue ncer where to start its add ress sequence.
8. The seq uencer addresses the m ic rocode memory u s i n g the pipe l i n e add ress b u s .
9. T h e m i c rocode memory s e n d s t h e appropriate instruction to t h e A L U s u s i n g the
A and B port add ress and ALUs i nstruction bus.
1 0. The designated i n stru ction is performed.
1 1 . When f i n ished with a com m and (or an error is detected), the FPP sends an i nterru pt
( l RQT3 L) to the system C P U .
1 2 . Steps 8 through 1 1 are repeated u n t i l the computation is com pleted . T h i s process
i n c l udes i nstructions for fetc h i n g data blocks from g l obal RAM.
1 3. The res u lt of the computation is stored in global RAM at an address previously specifie d
i n th e comm and stack.
1 4. The FPP fetches the next com m a nd stack.
1 5. Steps 5 through 1 3 are repeated u nt i l all the command sta c ks are done (u n l ess the
FPP is reset or an error is detected by the condition code m u ltiplexor).
1 6. The sequencer add resses the m i c rocode mem ory for the 'wait' command.
1 7. The wait com mand is executed using the constant pipe l i ne interface. The FPP rem a i n s
i n a wait loop u nt i l the next com mand add ress flag (AD D FLG) is sensed.
System Address Decoder and Handshake
the My Add ress s ignal (MYADDRSL) to activate the address PAL. The address PAL activates
the fo l lowi n g signals:
1 . Add ress F l ag (AD D FLG)
This s i g n a l l atches the system data bus i nto the command poi nter registers. (Th is d ata
is the starti ng add ress of the comm and stack i n g lobal RAM .)
2. Data Ack nowledge (DT ACK)
DT ACK is retu rned to the system C PU to indicate the com pletion of the FPP hand shake.
3. Cond ition Code (CCOD E)
CCO D E is sent to the sequencer. When the sequencer receives CCO D E , it b r a n c hes
out of wait l oop and starts the FPP p rocess.
ope rations.
C I RC U I T D E SC R I PT I O N S
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