HP 3562A, Руководство по обслуживанию

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MO D E L 3S62A
S E RVICE
LOCAL BUS
The local bus test shou ld be used to test the operation of the local data bus and the AM9S1 3
cou nter in the data point cou nter b lock. The local data bus is used by the system CPU
to com m u n icate with blocks on both DFA boards. See the block d iagrams for the AS,
A6 boards in Section VI. On the A6 board these blocks are the interrupts block, the measure­
ment state machine block, and the data pointer block. On the AS board this bus interfaces
to both d igital fi lter busses and the DMA bus.
This test must pass before any other DFA diagnostic self-test can pass. The local bus test
uses the AM9S1 3 cou nter (A6
U1 09)
to echo data on the local data bus (LDO to LD1 S)
through the system data bus interface. The test echos data several times, using a d ifferent
register in the cou nter each time. Therefore, the test can tel l a bus fai l u re from a cou nter
fai l u re.
Note that, since both DFA blocks exercised in this test (the system interface and the counter)
are on the A6 board, the AS board is not involved in this test other than to demonstrate
that bus interface circu its on the AS board are not inh ib iting the bus.
If this test fails, remove the AS Digital Filter assem bly and repeat the test. If the test sti l l
fails, start trou bleshooti ng the system data b u s interface and data point cou nter block
on the A6 board. If the test passes with the AS board removed, the fai l u re is on the AS
assembly; replace the AS assem bly and continue with the diagnostic tests.
If
Cl
bit passes any of the echos tests, the bus l i ne transm itting that bit is good . If that
bit is bad on every test, the bus l ine is probably defective. Any bit that passes some but
not all of the tests indicates a defective cou nter register.
If this test passes, the following su bb locks are probably fu nction ing correctly:
Data Point Cou nter
System Data Bus I nterface
System Add ress Decoder
DMA BUS
The DMA bus test shou ld be used, after the operation of the local data bus is verified,
to test the operation of the interface between the local data bus and the DMA bus and
the DMA control ler ICs.
This test is similar to the local bus test described previously except that the DMA control ler
ICs are used to echo data from the system CPU instead of the cou nter on the A6 board .
Refer to the block diagrams in Section VI to visualize the data path. The ci rcu its exercised
are the system data interface on the A6 board and the local data/DMA bus interface and
DMA control lers on the AS board.
If this test passes, the fol lowing are probab ly fu nction ing correctly:
Local Data Bus
DMA Bus
Local Data/DMA Bus I nterface
DMA control lers
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