User Guide

NPM-10 (3595)

System Module CC Technical Documentation

Implementation

The implemented concept, which is using three pads/connections between the phone

and the accessory cover, is shown in the following figure.

Figure 9: DC-OUT Interface

Detection of the cover is done via a "CTI" (Cover Type Indicator), which basically serves

the same purpose as the BSI resistors in the battery packs. Detection will be done in the

same way as currently used for the BSI. By using the "CTI", covers may be categorized

into different groups (i.e., current consumption).

The power section has a current-limited switch, and is controlled by a logic enable (on/

off) via KLIGHT. On/off will be synchronized with the "VIBRA" signal SW wise, but can

have independent SW control.

Keyboard

The keyboard used in NPM-10 (3595) is part matrix ("metal dome" type) and part individ-

ual interrupts. This is needed for supporting multiple key presses.

The keyboard PWB layout consists of a grounded outer ring and either a "cake pattern"

grid (matrix) or an inner pad. This construction makes the keys immune for ESD, as the

key dome will have a low ohmic contact with the PWB ground.

All lines are configured as input — when no key is pressed, the inputs are high since the

UPP has internal pull-up resistors on those lines. When a key is pressed, the specific lines

where the key is placed are pulled low. This generates an interrupt to the MCU and the

MCU now starts its scanning procedure.

Inside

phone

Cover

connection

Cover Type

Indicator

(resistor)

SLOWAD(6)

pass

sense

batt

lim

base

Enable

out

VFLASH1

100K

UIDRV(6)

"KLIGHT"

MIDI out

Cover

electronics

PWM out