User Manual

4
Publication 1794-IN064D-EN-P - March 2005
Description of Control Word 0
Filter Function Description
Use the filter in either 16-bit or 32-bit mode. Enable filter to use a triangular
shape waveform of frequencies as low as 1Hz. If the filter is not enabled, the
module will only function properly with input waveform of square shape.
Description of Control Word 1
Description of Control Word 2
Description of Control Word 2 Readback
Bit Description
Bit 0 Pulse Counting and period time measurement selection for Channel 0
0 = pulse counting and period time measurement selected - 16-bit
1 = period time measurement selected - 32-bit
Bit 01 Pulse Counting and period time measurement selection for Channel 1
0 = pulse counting and period time measurement selected - 16-bit
1 = period time measurement selected- 32-bit
Bit 02 Pulse Counting and period time measurement selection for Channel 2
0 = pulse counting and period time measurement selected - 16-bit
1 = period time measurement selected- 32-bit
Bit 03 Pulse Counting and period time measurement selection for Channel 3
0 = pulse counting and period time measurement selected - 16-bit
1 = period time measurement selected- 32-bit
Bit 04
Channel 0 - 0 = filter disabled; 1 = filter enabled
1
Bit 05
Channel 1 - 0 = filter disabled; 1 = filter enabled
1
Bit 06
Channel 2 - 0 = filter disabled; 1 = filter enabled
1
Bit 07
Channel 3 - 0 = filter disabled; 1 = filter enabled
1
Bits
08-09
09 08 Filter sample clock frequency and period (common to all
channels)
0 0 625kHz 1.6µs
0 1 312.5kHz 3.2µs
1 0 104.17kHz 9.6µs
1 1 7.8125kHz 128µs
Bits
10-15
Reserved
1
Use filter when the input waveform has slow rise/fall time or has high frequency noise on the
input waveform.
ATTENTION
Do not enable the filter with frequencies greater than
90kHz. A loss of counts may result.
Bit Description
00
Clock Frequency for period time measurement - Channel 0
0 = period time measurement with 10MHz internal clock selected
1 = period time measurement with 1MHz internal clock selected
01-03
03 02 01 Number of periods for measurement - Channel 0
0 0 0 1 period
0 0 1 2 period
0 1 0 4 period
0 1 1 8 period
1 0 0 16 period
1 0 1 32 period
1 1 0 64 period
1 1 1 128 period
04
Clock frequency for period time measurement - Channel 1 - refer to bit 00
05-07
Selection of number of periods for measurement - Channel 1 - see bits 01-03
08
Clock frequency for period time measurement - Channel 2 - refer to bit 00
09-11
Selection of number of periods for measurement - Channel 2 - see bits 01-03
12
Clock frequency for period time measurement - Channel 3 - refer to bit 00
13-15
Selection of number of periods for measurement - Channel 3 - see bits 01-03
Bit Description
00 Start new measurement - Channel 0 - when set, start new
measurement on positive edge
01 Start new measurement - Channel 1 - when set, start new
measurement on positive edge
02 Start new measurement - Channel 2 - when set, start new
measurement on positive edge
03 Start new measurement - Channel 3 - when set, start new
measurement on positive edge
04 Reset Counter, Channel 0 - a positive edge on this bit resets counter 01
05 Reset Counter, Channel 01- a positive edge on this bit resets counter 11
06 Reset Counter, Channel 2 - a positive edge on this bit resets counter 21
07 Reset Counter, Channel 3 - a positive edge on this bit resets counter 31
08-15 Reserved for factory use
Bit Description
00 Positive edge - Channel 0 - measurement ready
01 Positive edge - Channel 1 - measurement ready
02 Positive edge - Channel 2 - measurement ready
03 Positive edge - Channel 3 - measurement ready
04 Reset Counter, Channel 0 - a positive edge on this bit indicates counter 01
reset done
05 Reset Counter, Channel 1 - a positive edge on this bit indicates counter 11
reset done
06 Reset Counter, Channel 2 - a positive edge on this bit indicates counter 21
reset done
07 Reset Counter, Channel 3 - a positive edge on this bit indicates counter 31
reset done
08-15 Reserved for factory use