User`s guide

LZ87010 Advance User’s Guide Analog Inputs (ADC)
1/15/03 13-3
13.3 Registers
13.3.1 ADCC (ADC Control) Register
The ADCC (ADC Control) register contains the ADC’s configuration and status bits.
Table 13-2. ADCC Register
BIT 7 6 5 4 3 2 1 0
FIELD PWEN /// /// STATUS START SEL[2] SEL[1] SEL[0]
RESET 00000000
RW RW RW RW R RW RW RW RW
ADDR 0xC3
Table 13-3. ADCC Register Bits
BIT NAME DESCRIPTION
7PWEN
Power Enable Allows the ADC to be turned off when not in use to conserve power.
0 = Off
1 = On
6:5 /// Reserved Reads return ‘0’. Write as ‘0’.
4 STATUS
Status Read-only status bit. A ‘1’ indicates that the conversion is complete.
This bit is cleared on entry to the interrupt handler and when a new conversion
is started.
3START
Start Conversion To start a conversion, write a ‘1’ to this bit, followed by a ‘0’.
The time between these two writes defines the sampling window and must be at
least one ADCCLK period.
2:0 SEL[2:0]
Input Select Selects the analog input pin. The three-bit value maps directly
to AN[7:0]. The settling time of the ADC is the time between selecting the input
and the second write to ADCC.START (the ‘0’ that starts the conversion).