Flip; Flip Keyboard - Nokia NSB-9 Service Manual

NSB-9
System Module and User Interface
Flip position
Closed
Open
When no key is pressed row inputs are high due to UPP internal pull-up resistors. The
columns are written zero. When key is pressed one row is pulled down and an interrupt is
generated to MCU. After receiving interrupt MCU starts scanning procedure. All columns
are first written high and then one column at the time is written down. All other col-
umns except one which was written down are set as inputs. Rows are read while column
at the time is written down. If some row is down it indicates that key which is at the
cross point of selected column and row was pressed. After detecting pressed key all reg-
ister inside the UPP are reset and columns are written back to zero.
P10
P00 6
P01 Y
P02 H
P03 N
P04 SW right
P05 SW left
GenI/O 19 Shift

Flip

Part of the NSB-9 keyboard is implemented in a separate flip module, which is double
sided. Top side consists of so called ITU-T keys (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, * and #). On the
other side (inner side) there is a half of so called qwerty keys.
There are 4 contacts (2 in parallel) from engine to flip: Supply voltage, grounding, clock
and data lines. VBAT is used as flip power supply. There is a 1.8V / 50mA regulator inside
the flip for uController power supply. Upper VBAT voltage for flip is disabled with load
switch when flip is closed. When the flip is open, the lower VBAT voltage for the flip is
disabled with another loadswitch (U320)

Flip keyboard

4x9 matrix is used in flip keyboard. The matrix is connected to flip MCU. Character and
shift keys are connected to own inputs to enable simultaneus key pressings. Matrix key
pressing is detected with scanning. Character and shift keypressings are detected by I/O
port interrupts. Flip MCU is connected to the engine with serial data and clock lines (UPP
GenI/O17 and 18).
Page 30
Table 21: Power key function
Power key
Power key
3rd SW key
Table 22: Engine keyboard matrix
P11 P12
7 8
U I
J K
M ,
END Arrow up
SEND Space
Nokia Corporation
CCS Technical Documentation
Note
Right SW key is working as power key.
P13 P15
9 0
O P
L ;
. /
Arrow left Arrow right
Vol up Vol down
P15
Backspace
=
'
ENTER
Arrow down
Issue 1 04/03