XE8802 Datasheet, PDF (185/193 Pages) Semtech Corporation – Sensing Machine Data Acquisition MCU

XE8802 Sensing Machine Data Acquisition MCU
with ZoomingADC™ and LCD driver
21.1 Features
ƒ can be switched off, on or simultaneously with CPU activities
ƒ generates an interrupt if power supply is below a pre-determined level
21.2 Overview
The Voltage Level Detector monitors the state of the system battery. It returns a logical high value (an interrupt) in
the status register if the supplied voltage drops below the user defined level (Vsb).
21.3 Register map
There are two registers in the VLD, namely RegVldCtrl and RegVldStat. Table 21-2 shows the mapping of control
bits and functionality of RegVldCtrl while Table 21-3 describes that for RegVldStat.
register name
RegVldCtrl
RegVldStat
Table 21-1: Vld registers
pos.
7-4
3
2-0
RegVldCtrl rw
--
r
VldRange
rw
VldTune[2:0] r w
reset
0000
0
nresetglobal
000
nresetglobal
function
reserved
VLD detection voltage range for VldTune = “011”:
0 : 1.3V
1 : 2.55V
VLD tuning:
000 : +19 %
111 : -18 %
Table 21-2: RegVldCtrl
pos. RegVldStat rw reset
function
7-3 --
r 00000
reserved
2
VldResult
r 0 nresetglobal is 1 when battery voltage is below the detection
voltage
1
VldValid
r 0 nresetglobal Indicates when VldResult can be read
0
VldEn
r w 0 nresetglobal VLD enable
Table 21-3: RegVldStat
21.4 Interrupt map
interrupt source
IrqVld
default mapping in the interrupt manager
RegIrqMid(2)
Table 21-4: Interrupt map
© Semtech 2006
21-2
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