Sierra Video Yosemite User Manual

Page 68

SIERRA VIDEO

Diagnostic Startup Sequence

When the switcher is powered up or resets for any reason (as when a DIP Switch is changed), it performs
a series of self-tests, signaling progress using the DIP Array and Colored LEDs on the 505150 processor
board. The startup self-test sequence is fast but provides important diagnostic checks. The sequence is
as follows:

LED Startup Diganostics Sequence

Startup

Sequence

Initial LED

Combination

Operation

ALL LEDS

Flash quickly for about one second, immediately after
startup (after initializing the processor registers). This
indicates that the processor is up and running an that the
LEDs all work.

LEDa

Checksum of the flash memory is computed. If not 0,
LEDa is flashed for 3 seconds, then normal operation
begins. (Software note: the makefile uses the cksmfile
utility to set the flash checksum bytes so that the
checksum will be 0).

3 LEDb

LEDc

Both light and two primary RAMS are tested using a
pseudo-random number generator to create random
values. If any location tests “unhealthy”, LEDb and/or
LEDc is flashed for 3 seconds. Normal operation then
begins.

4 LEDd

LEDe

The non-volatile RAMS are tested by complementing
each word twice. If any location tests “unhealthy”,
LEDd and/or LEDe flash for 3 seconds. Normal
operation begins. LEDb flashes if an even-addressed
RAM location is bad, and LEDc flashes if an odd-
addressed RAM location is bad.

5 DIP

Switch

Setting

The values on the DIP Switches S4:S3 are displayed on
the LEDs for one second, then the values on DIP
switches S2:S1 are displayed for one second. This
allows the DIP Switches to be tested.

LEDf

Signals completion of startup self-test