Book Analog Interfacing to Embedded Microprocessors
occurred. If the ISR reads the index position, and the interrupt happens
in the middle of another command, the non-ISR code will get garbage data.
Figure 7.33 illustrates this. To avoid this condition, the software should
disable interrupts around non-ISR code (or interruptible ISR code) that
accesses the LM628/9.
These restrictions are typical but not unique to the LM628/9. There are
other motor controller ICs available as well, and all have their quirks.
The MC2300 series from Precision Motion Devices (PMD) is a two-chip set
that can control up to four brushless DC motors. These parts can control two-
or three-phase brushless motors and can provide several motion profiles. The
MC2300 can provide a digital word for a DAC/amplifier driver, or PWM
outputs for an H-bridge.
The MC2100 series, also from PMD, is a two-chip set for brushed DC
motors. Like the MC2300, the MC2100 parts support 1 to 4 motors, have 32-
annaabi.ee 
