IBM AR-B3001, Manual, Page: 18 / 41

ACROSSER TECHNOLOGY
18
3.4 DATA REGISTER (BASE+1)
Read Data Register will get the converted data. Since the
A/D data is 12-bit, low byte data and high byte data need
be read separately. Set DL of Control Register to 1 and
DH to 0 will read the low byte. Set DL of Control Register
to 0 and DH to 1 will read high byte of data. The format
of low byte and high byte data are describes as followings:
Base + 1(Control Register DH=0,DL=1)
D7 D6 D5 D4 D3 D2 D1 D0
AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0
Base + 1(Control Register DH=1,DL=0)
D7 D6 D5 D4 D3 D2 D1 D0
0 0 0 SIGN AD11 AD10 AD9 AD8
AD11 to AD0
Analog to digital data. AD0 is LSB and AD11 is
MSB. Data is stored as binary.
POL
Polarity bit. If input voltage is positive (greater than
0), this bit will be 1. If input voltage is negative, This
bit will be 0.
OVR
Over range. If the input voltage is out of range (-5V
to +5V), this bit will be 1.
X Don't care.