HP 3562A Service Manual page 558

S E RV I C E
G LO BAL I NT E RFACE T E ST
This tests moves (copies) a block of data from one area of g lobal RAM to another area.
It exercises both i nterrupt c i rcu its and the add ress c ircu itry besides testi ng the gl obal i nter­
face c i rcu its.
The CPU instru cts the FFT to do a b lock move, waits for the FFT to s ignal that it has fin ished
the process, and then compares val ues of the two areas of RAM to dete rm ine whether
the data copied !s identical to the original data.
B. A9 Signature Analysis Tests
There are three digital s ignatu re tests designed to test the d ig ital c i rcu its on the FFT board.
These tests are referred to by n u m ber as tests 1 , 2, and 3 .
Test 1 tests the program ROMs (U301 a n d U 303) and, to a l i m ited extent, the TMS320
microprocessor. See table A9-2 for the signatures of test 1 . With J3 and J 4 in the test position
(marked with a "T") the ROM output l i nes are d iscon nected and the TMS320 data l i nes
are grou nded. T h i s test m ay be u sed to test the i nput and output signals of the ROM
i ntegrated c i rcu its. The operation of the m icroprocessor is partially verified by this test
because the add ress l i ne outputs of the TMS320 are identical to the ROM i n put l i nes.
Test 2 may be used to test most of the c i rcu its on the FFT board. The only exceptions
are the global bus interface c i rcu its. These req u i re a special clock and are covered in test 3.
Test 3 may be used to test the g l obal b u s i nte rface c i rcu its (U51 1 through U51 6) and the
coefficient ROM outputs (U31 5 and U31 7). This test uses the memory grant signal on test
point 3 as a c lock. See the table for test 3 .
Perform the fol lowing steps to configure the instrument for any of the three d igital signature
tests:
• D i scon nect the power cable.
•
Put the FFT board on an extender card. A l l j u m pers should be i n the normal (N)
position.
• Select the signature test you wish to pe rfo rm.
• Connect and conf i g u re the signature ana lyzer as descri bed i n the tab le at the
beg i n n i n g of the test you wish to perform.
• Con nect the power cable and tu rn on power.
1 . Digital Si gnatu re Test 1
Table A9-1
Signal
G round
Clock
Stop
Start
8-1 08
FFT Signature Analyzer Setup #1
Polarity
Neg edge
Neg edge
Pos edge
Connection
A7 ) 5-1
A7 ) 5-3
A7 ) 5-4
A7 ) 5-5
MO D E L 3562A