BitsyXb - User Manual
44
110118-0001A
Several volume production options are available and are indicated by dashed lines in the diagram
above. Options are available for production customers, as described in section 6.1.4, but are
otherwise outside the scope of this manual. Contact your Eurotech sales representative if you
believe one or more of these options are required for your application.
Specifications for the BitsyXb power supply are listed in section 6.3.4.
5.2.2
Subsystem Partitioning
The BitsyXb can selectively turn off power to subsystems on the board. This load-shedding
feature can extend battery life and significantly increase the amount of time the supercapacitors
will hold up system power. Applications and the operating system determine how selective power
management is utilized.
BitsyXb systems that can be selectively disabled include the following:
•
LCD display (panel power and signal buffers)
•
Vee (contrast control)
•
Audio output amplifier
•
Audio codec and microphone pre-amps
•
Serial 1 and 3 EIA-232 buffers
•
External device 1 (/PE1, J3.42)
•
External device 2 (PE2, J3.24)
In addition, the BitsyXb also controls its core power supplies to support sleep operation:
•
Vcc (5 V) supply
•
Vddx (3.3 V) and Vddi (processor core) supplies