Watchdog: Difference between revisions

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The watchdog is a down counter clocked with the [[68k]] (?), which resets the system if it underflows.
The watchdog is an anti lock-up/protection feature in AES/MVS system: A resettable down counter located in the [[NEO-B1]] chip resets the system if it underflows.


"Kicking" it resets the counter to its highest value.
It must be therefor "kicked" regularly to reset the counter to its highest value, this is done by writing any byte to register REG_DIPSW ($300001).
Games [[68k interrupts|VBlank]] routines often take care of this task.


Write any byte to register REG_DIPSW ($300001), to kick the watchdog on AES/MVS systems.
Constantly resetting systems produce a typical clicking sound (due to ?), giving a clue for solving boot issues.


CD systems don't have a watchdog.
CD systems don't have a watchdog.
(Sound file ?)


[[Category:Code]]
[[Category:Code]]
[[Category:CPUs]]
[[Category:CPUs]]

Revision as of 13:34, 8 February 2011

The watchdog is an anti lock-up/protection feature in AES/MVS system: A resettable down counter located in the NEO-B1 chip resets the system if it underflows.

It must be therefor "kicked" regularly to reset the counter to its highest value, this is done by writing any byte to register REG_DIPSW ($300001). Games VBlank routines often take care of this task.

Constantly resetting systems produce a typical clicking sound (due to ?), giving a clue for solving boot issues.

CD systems don't have a watchdog.

(Sound file ?)