XE8805 SEMTECH [Semtech Corporation], XE8805 Datasheet - Page 152

• Manufacturer Part Number: XE8805
• Description: Data Acquisition MCU
• Manufacturer: SEMTECH [Semtech Corporation]

21.1 Features
•
•
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 221-1 shows the mapping of
control bits and functionality of RegVldCtrl while Table 221-2 describes that for RegVldStat.
21.4 Interrupt map
21.5 VLD operation
The VLD is controlled by VldRange, VldTune and VldEn. VldRange selects the voltage range to be detected,
while VldTune is used to fine-tune this voltage level in 8 steps. VldEn is used to enable (disable) the VLD with a
1(0) value respectively.
Disabled, the block will dissipate no power.
© Semtech 2006
Can be switched off, on or simultaneously with CPU activities
Generates an interrupt if power supply is below a pre-determined level
pos.
7-3
2
1
0
pos.
7-4
3
2-0
RegVldStat
--
VldResult
VldValid
VldEn
RegVldCtrl
--
VldRange
VldTune[2:0]
interrupt source
IrqVld
rw
r
r
r
r w
rw
r
r w
r w
reset
00000
0 resetsystem
0 resetsystem
0 resetsystem
reset
0000
0 resetsystem
000
resetsystem
Table 221-3: Interrupt map
Table 221-2: RegVldStat
Table 221-1: RegVldCtrl
mapping in the interrupt manager
21-2
function
reserved
is 1 when battery voltage is below the detection
voltage
Indicates when VldResult can be read
VLD enable
function
reserved
VLD detection voltage range for VldTune = “011”:
VLD tuning:
000 : +19 %
111 : -18 %
0 : 1.3V
1 : 2.55V
RegIrqMid(2)
XE8805/05A
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