HP Vectra Technical Reference Manual page 169

5.3.3 Logical Keyboard Driver
The logical keyboard driver determines the keypad group the scancode belongs to and sets the
Data type field in the ISR event record. Based on the Data type a translator service is called to ..., .
handle the scancode. For example, If the "Q" key scancode comes through, the logical keyboard .,
driver determines the data type to be T_KC_QWERTY and calls the V_QWERTY translator. If
the translator called by the logical keyboard driver is responsible for any of the keyboard modifier
keys the current state variable is placed in the ISR Event Record and the state indicator bit is set
in the Data Type field. Table 5.12 contains the scancode range to translator service assignments.
Table 5.12
Scancode to Translator Assignments
Driver Name
V_QWERTY
V_SOFTKEY
V_FUNCTION
V_NUMPAD
V_CCP
Scancode Range
OOH-36H
38H-3AH
55H-5FH
6BH-6FH
78H-7FH
70H-77H
3BH-44H
37H, 45H-54H
60H-6AH
Translation Performed
None
3BH-42H (F1-F8)
None
None
Cursor Always-Regardless of state of the
<
Num lock> and
<
Shift> keys.
If the translation was successful the returned ISR Event Record is passed to the logical keyboard
drivers parent (V_8041).
Before passing a successful translation to its parent (V_8041) the logical keyboard driver
performs two conditional tasks. First, it checks the state bit in the returned Data Type, if set the
master copy of the keyboard state variable is updated with the copy returned in the ISR Event
Record. Second, if the ISR event went to the V_CCP translator the logical keyboard driver takes
the necessary steps to insure that cursor control keys are generated regardless of the
<
num
lock> and
<
shift> key states.
If a translator wants to remove the scancode from the scancode stream it must return a status
code of RS_DONE to the logical keyboard driver (See the CCP2GID driver in Appendix G).
Table 5.13 contains a summary of the logical keyboard driver functions.
160 Keyboard