Digital Equipment VAXstation I Service Manual page 71

MAIR'.l'BNANCE
Table 3·8: VCBOl Diagnostic Tests (continued)
+· - . ·+· - - - - - - . - - - - - - - - .. - - - . - - - - . - - - - . - - - - - .. - - - - - - . - - - - . - - - - - - -+
[TEST! DESCRIPTION
I
+-. - ·+-. - . - - - - - - - - . - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .. - -+
3 INTERRUPT CONTROLLER R/W -- Tests the internal functions
of the Interrupt Controller chip, with interrupts
turned-off at the CSR and the Interrupt Controller.
(Because interrupts are turned-off, the Interrupt
Controller response memory is not tested.)
4 INTERRUPT CONTROLLER INTERRUPT TEST •· An Interrupt
Controller internal test, including response memory, with
interrupts enabled, using fixed and rotating interrupts.
5 DUART REGISTER R/W TEST -- Tests all the internal
read/write registers in UARTs A· and B, using all-ones,
all-zeros, and alternating ones-and-zeros data patterns.
6 DUART LOOPBACK TEST -~ Using the chip's internal loopback
facilities, verifies that both UARTs can transmit data at
all baud rates. The patch panel and cables can be tested
if an external loopback connector is used and the
appropriate event flag is set.
7 DUART INTERRUPT DRIVEN LOOPBACK TEST -- Using the
Interrupt Controller to drive the software, this :est
verifies that data can be transmitted through the DUART.
The patch panel and cables will be tested if an external
loopback connector is used; otherwise, only the internal
loopback path will be tested.
8
9
CURSOR TEST .. Tests the CRTC and the Cursor
the video readback path, the following
checked for valid responses:
o cursor positioning
o cursor RAM
o cursor-generated interrupts
o cursor enable/disable
RAM. Using
functions are
SCAN LINE MAP TEST .. Tests each word in the Scan Line Map
RAM. Data patterns are written into the RAM and verified
using the video readback path.
3-17