nRF24E1 Nordic VLSI, nRF24E1 Datasheet - Page 41

• Manufacturer Part Number: nRF24E1
• Description: 2.4Ghz RF Transceiver With Embedded 8051 Compatible Microcontroller And 9 Input, 10 Bit ADC
• Manufacturer: Nordic VLSI

PRODUCT SPECIFICATION
Table 5-3 : ADC data SFR-registers, SFR 0xA2 and 0xA3.
A signal ADC_EOC is available in the EXIF.4 bit (Interrupt 2 flag) and it is set to 1
by A/D converter when conversion requested by CSTARTN is completed, see Table
7-4 : EXIF Register – SFR 0x91
When EXTREF (ADCCON.4) is set to 1 and ADCSEL (ADCCON.3-0) selects an
input AIN
the ratio between the voltage on the selected input, and the voltage on pin AREF.
AINi voltage = AREF voltage * ADCDATA / 2
Where N is the number of bits set in ADCRES (ADCSTATIC.1-0) and ADCDATA is
the resulting bits in ADCDATAH (and ADCDATAL if N > 8).
For differential measurements a simular equation apply :
(AINi - AIN
This mode of operation is normally selected for sources where the voltage is
depending on the supply voltage (or another variable voltage), like shown in Figure
5-2 below. The resistor R1 is selected to keep AREF
voltage.
Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone [phone] - Fax [phone]
Revision: 1.0
7 - 0
7 - 4
3
2
1
0
i
ADCUF
ADCOF
ADCRNG
( e.g. AIN
0
)voltage = AREF voltage * (ADCDATA -2
0
to AIN
Most significant 8 bits of A/D converter result. For 6-bit
conversions ADCDATAH.7-6 is ‘00’
Least significant part of A/D converter result when
resolution is 12 or 10 bits, leftjustified. For 10-bit
conversions ADCDATAH.5-4 is ‘00’
not used
Underflow in conversion. Data is all 0’s
Overflow in conversion. Data is all 1’s
Overflow or underflow in conversion
(ADCUF | ADCOF)
7
), the result in ADCDATAx is directly proportional to
QhtrÃ# ÂsÃ(&
**N
**(N-1)
) / 2
**N
July 2003