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for ARM devices
KeyV 4
Programmer's Reference Manuals
» Part 1 - Introduction
» Vectors
» Software Vector Numbers
» KeyV
» KeyV 4
» Enable keyboard device drivers
| Entry | |
|---|---|
| R0 | 4 (reason code) |
Use
KeyV 4 is called by the kernel to enable keyboard device drivers.
Notes
The key released (KeyV 1) and key pressed (KeyV 2) reason codes must not be used by the device driver until it receives this reason code.
This is not a reset call and may be seen many times whilst the device driver is active. It does mean that the kernel has flushed its table of keys that are held down, so the device driver should do the same if appropriate.