Hardware Manual - RTD Embedded Technologies, Inc.

Programming Channel, Gain, Input Range, and Type
The conversion channel, gain, input range, and input type are programmed at BA + 0x04h. To program a
conversion channel for direct A/D conversion (not using the channel-gain table), you must first point
BA + 0x04h to write to the channel/gain latch. This is done by setting bits 0 and 1 to "00" in the Control Register
at BA + 0x02h. To program the channel, gain, input range, and input type, assign the appropriate values to bits
0 through 10 and write this value to BA + 0x04h. The diagram below shows this register.
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
0 0 0 0 0
A/D SE/DIFF
0 = single-ended
1 = differential
A/D Input Range/
Polarity Select
00 = ±5 V
01 = ±10 V
10 = 0 to +10 V
11 = reserved
Gain Select
000 = x 1
001 = x 2
010 = x 4
011 = x 8
100 = reserved
101 = reserved
110 = reserved
111 = reserved
Analog Input
Channel Select
00000 = channel 1
00001 = channel 2
00010 = channel 3
00011 = channel 4
00100 = channel 5
00101 = channel 6
00110 = channel 7
00111 = channel 8
01000 = channel 9
01001 = channel 10
01010 = channel 11
01011 = channel 12
01100 = channel 13
01101 = channel 14
01110 = channel 15
01111 = channel 16
•
•
•
11111 = channel 32
The program sequence for programming the channel and gain not using the channel-gain scan memory is:
1. Set bits 1 and 0 at BA + 0x02h to 00 (this points BA + 0x04h to the channel/gain latch).
2. Write the channel and gain data to be loaded to BA + 0x04h.
BDM-610010034 Rev C Chapter 5: A/D Conversions 63