HT66F20_1006 Datasheet, PDF (134/250 Pages) Holtek Semiconductor Inc – Enhanced A/D Flash Type MCU 8-Bit MCU with EEPROM

HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
· ADCR0 Register
¨ HT66F60
Bit
Name
R/W
POR
7
START
R/W
0
6
EOCB
R
1
5
ADOFF
R/W
1
4
ADRFS
R/W
0
3
ACS3
R/W
0
2
ACS2
R/W
0
1
ACS1
R/W
0
0
ACS0
R/W
0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3~0
START: Start the A/D conversion
0®1®0 : start
0®1 : reset the A/D converter and set EOCB to ²1²
This bit is used to initiate an A/D conversion process. The bit is normally low but if set high and
then cleared low again, the A/D converter will initiate a conversion process. When the bit is set
high the A/D converter will be reset.
EOCB: End of A/D conversion flag
0: A/D conversion ended
1: A/D conversion in progress
This read only flag is used to indicate when an A/D conversion process has completed. When
the conversion process is running the bit will be high.
ADOFF : ADC module power on/off control bit
0: ADC module power on
1: ADC module power off
This bit controls the power to the A/D internal function. This bit should be cleared to zero to
enable the A/D converter. If the bit is set high then the A/D converter will be switched off reducing
the device power consumption. As the A/D converter will consume a limited amount of power,
even when not executing a conversion, this may be an important consideration in power sensitive
battery powered applications.
Note: 1. it is recommended to set ADOFF=1 before entering IDLE/SLEEP Mode for saving
power.
2. ADOFF=1 will power down the ADC module.
ADRFS: ADC Data Format Control
0: ADC Data MSB is ADRH bit 7, LSB is ADRL bit 4
1: ADC Data MSB is ADRH bit 3, LSB is ADRL bit 0
This bit controls the format of the 12-bit converted A/D value in the two A/D data registers.
Details are provided in the A/D data register section.
ACS3, ACS2, ACS1, ACS0: Select A/D channel (when ACS4 is ²0²)
0000: AN0
0001: AN1
0010: AN2
0011: AN3
0100: AN4
0101: AN5
0110: AN6
0111: AN7
1000: AN8
1001: AN9
1010: AN10
1011: AN11
1100~1111: undefined, can¢t be used
These are the A/D channel select control bits. As there is only one internal hardware A/D
converter each of the eight A/D inputs must be routed to the internal converter using these bits.
If bit ACS4 in the ADCR1 register is set high then the internal 1.25V will be routed to the A/D
Converter.
Rev. 1.20
134
June 4, 2010