MAX11041 Maxim, MAX11041 Datasheet - Page 13

• Manufacturer Part Number: MAX11041
• Description: The MAX11041 wired remote controller converts up to 30 different pushbuttons into an I²C register
• Manufacturer: Maxim

Certain applications require the detection of
simultaneous keypresses, such as <SHIFT+KEY> and
<FUNCTION+KEY> combinations. This is done in
software. For instance, the µP detects the SHIFT key is
being pressed. When the µP detects an additional key-
press instead of a key release, it knows the corre-
sponding code is a result of two resistors
in parallel.
Some applications require detection of the specific
sequence of keys in software by looking for unique key
presses within 32 ticks (1s). If the duration between
keypresses exceeds the allowed time, assume the key-
press is in error and return to the previous known state.
Figure 10 illustrates the FIFO entries during a typical
sequence of events.
Position R
possible. Bypass V
close to the device as possible. Connect GND to a
quiet analog ground plane. Route digital lines away
from SENSE and FORCE.
Power-Up Jack Detect and Keypress
SENSE
and C
___________________________________________________________________________________
Layout, Grounding, and Bypassing
DD
Simultaneous Keypress Detection
with a 0.1µF capacitor to GND as
SENSE
Order of Keypress Detection
as close to the device as
Example
Wired Remote Controller
Figure 10. Software Implemented Hold-Switch Configuration
FORCE
WIRED REMOTE CONTROLLER
R
R
R
SW0
SW30
SW1
R
JACK
HOLD SWITCH
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