HP 1660 Series Service Manual page 215

Theory of Operation
System Tests (System PV)
HP-I B Test HP-I B Test
The HP-IB test performs a write/read operation to each of the registers of the HP-IB IC. A
test pattern is written to each register in the HP-IB IC. The pattern is then read and
compared with a known value.
Passing the HP-IB test implies that the read/write registers in the HP-IB IC can store a logical
"1" or a logical "0," and that the HP-IB IC is functioning properly. Incoming and outgoing
HP-IB information will not be corrupted by the HP-IB IC.
RS-232C Test RS-232C Test
This test checks the basic interface functions of the RS-232C port. Both internal and
external portions of the port circuitry are tested. In order for the RS-232C test to pass, the
RS-232C loopback connector must be installed on the RS-232C connector.
HI L Test HI L Test
The HIL test exercises both the HIL circuitry internal to the logic analyzer and the HIL
interface between the logic analyzer and external keyboard, if an external keyboard is
connected. First, a read/write operation is performed to each of the registers of the HIL IC.
A test pattern is written to each memory location, read, and compared with a known value.
Second, if an external keyboard is connected to the HIL port, the keyboard controller that
resides in the keyboard is polled by the microprocessor. A test pattern is sent to the
keyboard controller and returned to the microprocessor by the keyboard controller. The test
pattern is then compared with a known value.
Passing the HIL test implies that the read/write registers in the HIL IC can store a logical "1"
or a logical "0," and that the HIL IC is functioning properly. Also, passing the HIL test implies
that the HIL pathway to the external keyboard is functioning and that the keyboard
controller can communicate with the microprocessor in the logic analyzer. Incoming HIL
information from the external keyboard will not be corrupted by the pathway between the
keyboard controller and microprocessor.
Di sk Test Di sk Test
The disk test exercises the disk controller circuitry by performing a read/write on a disk.
Either an LIF formatted disk with 20 sectors available space or a DOS formatted disk with 5K
available space is required and should be inserted in the disk drive. When the disk test is
executed, the disk is checked sector by sector to find any bad sectors. If no bad sectors are
found, a test file is created on the disk and test data is written to the file. Then, the file is
read and the test data is compared with known values. At the conclusion of the test, the test
file is erased.
Passing the disk test implies that the disk controller circuitry in the logic analyzer and the
disk read/write circuitry in the disk drive are functioning properly. The disk drive can read
and write to a LIF or DOS formatted disk, and the data will not be corrupted by the disk drive
circuitry.
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