Technologic Systems TS-7200, User Manual, Page: 22 / 52

5 A/D Converter
Table 5a A/D Registers
I/O Address Action
10C0_0000 Write Initiate A/D Conversion
10C0_0000 Read LSB of Conversion
10C0_0001 Read MSB of Conversion
2240_0000 Read Bit 0 = 1 if A/D option installed
1080_0000 Read Bit 7 = 0 when Conversion completed
The TS-7200 supports an optional
eight-channel, 12-bit A/D converter
(ADC) with a conversion time of 12
uS. This will allow up to 60,000
samples per second. Each channel
is independently software
programmable for a variety of
analog input ranges: -10V to +10V, -
5V to +5V, 0V to +10V, or 0V to
+5V. This allows an effective
dynamic range of 14 bits.
Table 5b A/D Control Register (0x10C0_0000 Write)
Bit Description Details
0-2 Analog channel select Channels 0-7
3
Unipolar / Bipolar 0 = Unipolar (i.e. 0 to +5V)
1 = Bipolar (i.e. -5V to +5V)
4 Range select 0 = 5V range
1 = 10V range
5-7 Mode bits Set to 0, 1, 0
Each channel is overvoltage tolerant
from -16V to + 16V, and a fault
condition on any channel will not
affect the conversion result of the
selected channel. This is all
accomplished with a 5V only power
supply; no negative supply voltage
is required. The Maxim MAX197
chip can be replaced with a
MAX199 chip if a lower range of
analog input levels is required (-4V
to +4V, -2V to +2V, 0V to 4V, and 0V to 2V).
A read at I/O location
0x2240_0000
bit 0 returns a "1" when the A/D option is installed
on the TS-7200.
TS-7200 User's Manual Technologic Systems http://www.embeddedARM.com/
18 12/2004