EM78P258N
8-Bit Microprocessor with OTP ROM
Bit 4 (ADRUN):
ADC starts to RUN.
1 = an AD conversion is started. This bit can be set by
software.
0 = reset on completion of the conversion. This bit
cannot be reset though software.
Bit 3 (ADPD):
ADC Power-down mode.
1 = ADC is operating
0 = switch off the resistor reference to save power even
while the CPU is operating.
Bit 2:
Not used
Bit 1 ~ Bit 0 (ADIS1 ~ ADIS0): Analog Input Select
00 = ADIN0/P50
01 = ADIN1/P51
10 = ADIN2/P52
11 = ADIN3/P53
These bits can only be changed when the ADIF bit and
the ADRUN bit are both LOW.
6.7.1.3 RA (ADOC: AD Offset Calibration Register)
7
6
5
4
3
2
1
0
CALI
SIGN
VOF[2]
VOF[1]
VOF[0]
–
–
–
Bit 7 (CALI): Calibration enable bit for ADC offset
0 = Calibration disable
1 = Calibration enable
Bit 6 (SIGN): Polarity bit of offset voltage
0 = Negative voltage
1 = Positive voltage
Bit 5 ~ Bit 3 (VOF[2] ~ VOF[0]): Offset voltage bits.
VOF[2]
VOF[1]
VOF[0]
EM78P258N ICE259N
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0LSB
2LSB
4LSB
6LSB
8LSB
10LSB
12LSB
14LSB
0LSB
1LSB
2LSB
3LSB
4LSB
5LSB
6LSB
7LSB
Bit 2 ~ Bit 0: Unimplemented, read as ‘0’.
44 •
Product Specification (V1.0) 06.16.2005
(This specification is subject to change without further notice)
ELAN [ ELAN MICROELECTRONICS CORP ]
