DSC Brings NanoEdge PWM To Motor And Power Control
Freescale MC56F82xx block diagram
Freescale TWR-56R8267 Tower module
Freescale has always been known for supplying high performance digital signal controllers (DSC) and digital signal processors (DSP) for motor control and power management systems. The Freescale MC56F82xx continues this tradition with a 60 MHz 56800E DSC core and NanoEdge PWMs the provide precise timing for these applications.
The The MC56F82xx architecture (Fig. 1) is pretty conventional. It has on-chip flash and RAM plugs a selection of communication peripherals including a CAN controller, an SPI port, two SCI ports and a pair of SMBus/I2C ports. The dual 12-bit, 8-channel ADCs have programmable gain amplifiers and a 500ns conversion rate. The 3 analog comparators, 12-bit DAC and three 5-bit DACs round out the analog peripherals. The 54 GPIOs are 5V tolerant.
There are eight 16-bit enhanced timers but the key is the NanoEdge PWMs with a 520ps duty cycle resolution. The NanoEdge technology essentially allows a designer to precisely position the edge of the PWM pulse with a higher accuracy than the counters used to determine the length and position of the pulse. The additional precision essentially provides a higher resolution timer needed for motor control and power applications. The eFlexPWM controller can handle center, edge-aligned and asymmetrical timing chores. It has double buffered registers with integral reload rates and half-cycle reload capabilities.
Developers can take advantage of Freescale's CodeWarrior IDE. The software package includes motor and power control examples. Applications can be developed using Freescale's Tower system and the TWR-56R8267 Tower module (Fig. 2). This module can plug into a Tower system stack where developers can include their own modules.
The pricing for the MC56F82xx family starts at $2.70. The TWR-56R8267 Tower module is priced at $79.