pc87591l National Semiconductor Corporation, pc87591l Datasheet - Page 185

• Manufacturer Part Number: pc87591l
• Description: Lpc Mobile Embedded Controllers
• Manufacturer: National Semiconductor Corporation

Revision 1.07
Embedded Controller Modules
Voltage Channel 3 Control Register (VCHN3CTL)
This register controls the operation and indicates the status of Voltage Channel 3. VCHN3CTL is set to 1F
Location: 00 FF3C
Type: Varies per bit
Voltage Channel 3 Data Buffer (VCHN3DAT)
This register (buffer) holds the data measured by Voltage Channel 3.
Location: 00 FF3E
Type: RO
4.11.7 Usage Hints
Power Supply and Layout Guidelines
For more information, see Section 3.1.3 on page 63.
Power Consumption
ADC power consumption from the analog supply (AV
ADCCNF register to 0.
When the ADC is enabled, the current consumption depends on the channel type measured (voltage or temperature) and
the ADC clock frequency. To minimize current consumption, disable the ADC when not in use. See details in “Enabling and
Disabling the ADC” on page 174.
Back-Drive Protection
To maintain the high performance of the analog circuits, AD(0-7), AD8/DP and AD9/DN pins are not back-drive protected.
Therefore, the voltage applied to these pins must be within the AGND to AV
aged. External circuits should not drive currents into these pins when the PC87591x is not powered up.
Measuring Out of Range Voltages
The ADC is capable of measuring positive input voltages from 0V to V
divided or level-shifted, as required.
Bit
Name
Reset
Bit
Name
15-10 Reserved.
9-0
Bit
4-0
Bit
5
6
7
VCHDAT (Voltage Channel 3 Data). Same as Voltage Channel 1.
R/W1C DATVAL (Data Valid). Same as Voltage Channel 1.
Type
R/W
R/W
R/W
15
DATVAL
SELIN (Selected Input). Same as Voltage Channel 1.
INTDVEN (Interrupt from Data Valid Enable). Same as Voltage Channel 1.
CSCALE (Channel Scale). Same as Voltage Channel 1.
16
16
7
0
14
Reserved
CSCALE
13
6
0
12
INTDVEN
11
(Continued)
5
0
10
CC
) is practically zero if the ADC is disabled by setting ADCEN in
9
Description
185
4
1
Description
8
FS
7
. Input voltages outside this range should either be
3
1
CC
6
range; otherwise, the device may be dam-
VCHDAT
5
SELIN
2
1
4
3
1
1
2
16
on reset.
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1
0
1
0