DEC Digital Alpha VME 4/224 User Manual page 98

DALLAS DS1386 RAMified Watchdog Timekeeper Tests
Console Command: ds1386_diag -t 3
Command Options:
• -dd: print detailed test information on each pass.
• -nqv: test every location in NVRAM, default is to test 1 location per 256 byte
page.
Miscellaneous Note
This diagnostic is an extended test.
TOY Clock Bitwalk Test
This diagnostic does a walking 1, walking 0, and A5 register test on the time-of-
year (TOY) clock registers. It also tests the rollover cases associated with keeping
time.
The watchdog reset enable bit in the module control register is set to zero to
ensure that a watchdog expiration does not cause a hardware reset to occur.
Secondly, the contents of the command register is saved and the transfer enable
bit is set to 0 to disable updates to the registers while the diagnostic is in
progress.
The diagnostic bit patterns are then walked through all 14 registers. Next, the
seconds, minutes, hours, day, month, and year registers are programmed such
that the next clock tick rolls over for each of these parameters. The updates to
the registers are started and updated for a three second time period. After the
three second update period, the registers are then examined to verify that each
parameter did indeed roll over to the appropriate value.
The diagnostic cleans up by reenabling the watchdog reset bit in the module
control register and restoring the original contents of the TOY clock command
register.
The current date and time has to be reset after invoking this diagnostic
test since approximately 3 seconds of time is lost for each pass.
4–20 Diagnostics
Note