MC2400 Datasheet, PDF (53/59 Pages) List of Unclassifed Manufacturers – Navigator Motion Processor

6.9 16-bit A/D Input
The interface between the Navigator chipset and 16 bit A/D converters as parallel input position
devices is shown in the following figure.
Comments on Schematic
The schematic shows a 16 bit A/D used to provide parallel position input to axis 1 and axis 2. The
expansion to the remaining two axes is easily implemented. The 374 registers are required on the
output of the A/D converters to make the 68-nanosecond access time of the CP. The worst-case
timing of the A/D’s specify 83 nanoseconds for data on the bus and 83 nanoseconds from data to
tri-state on the bus. Each time the data is read the 169 counter is set to 703 decimal. This provides a
35.2-microsecond delay before the next conversion. With a 10-microsecond conversion time the
data will be available for the next set of reads after 50 microseconds. The delay is used to provide a
position sample close to the actual position.
MC2400 Technical Specifications
53