ADMCF341

20 MHz Fixed-Point DSP Core
Single-Cycle Instruction Execution (50 ns)
ADSP-21xx Family Code Compatibility
Independent Computational Units
ALU, Multiplier/Accumulator, Barrel Shifter
Multifunction Instructions
Single-Cycle Context Switch
Powerful Program Sequencer
Zero Overhead Looping
Conditional Instruction Execution
Two Independent Data Address Generators
Memory Configuration
512 16-Bit Data Memory RAM
512 24-Bit Program Memory RAM
4K 24-Bit Program Memory ROM
4K 24-Bit Program Flash Memory
Three Independent Flash Memory Sectors
3584 24-Bit, 256 24-Bit, 256 24-Bit
Low-Cost Pin-Compatible ROM Option
16-Bit Watchdog Timer
Programmable 16-Bit Internal Timer with Prescaler
Two Double Buffered Serial Ports with SPI Mode Support
Integrated Power-On Reset Function
Three-Phase 16-Bit PWM Generation Unit:
16-Bit Center-Based PWM Generator
Programmable PWM Pulsewidth
Edge Resolution to 50 ns
153 Hz Minimum Switching Frequency
Double/Single Duty Cycle Update Mode Control

Individual Enable and Disable for Each PWM Output
High-Frequency Chopping Mode for Transformer
Coupled Gate Drives
External PWMTRIP Pin
Integrated 6-Channel ADC Subsystem
Three Bipolar ISENSE Inputs with Programmable
Sample-and-Hold Amplifier and Overcurrent Pro-
tection (Usable as Three Dedicated Analog Inputs)
Muxed Auxiliary Analog Inputs
Internal Voltage Reference (2.5 V)
Acquisition Synchronized to PWM Switching
Frequency
9-Pin Digital I/O Port
Bit Configurable as Input or Output
Change of State Interrupt Support
Two 16-Bit Auxiliary PWM Timers
Synthesized Analog Output
Programmable Frequency
0% to 100% Duty Cycle
Two Programmable Operational Modes
Independent Mode/Offset Mode
Motor Types
Permanent Magnet Synchronous Motors (PMSM)
Brushless DC Motors (BDCM)
AC Induction Motors (ACIM)

The ADMCF341 is a low-cost, single-chip DSP-based control-ler, suitable for permanent magnet synchronous motors, acinduction motors, and brushless dc motors. The ADMCF341 integrates a 20 MHz, fixed-point DSP core with a complete set of motor control and system peripherals that permits fast, efficient development of motor controllers.

The DSP core of the ADMCF341 is completely code-compatible with the ADSP-21xx DSP family and combines three computa- tional units, data address generators, and a program sequencer.

The computational units are an ALU, a multiplier/accumulator (MAC), and a barrel shifter. There are special instructions for bit manipulation, multiplication ( squared), biased rounding, and global interrupt masking. The system peripherals are the power-on reset circuit (POR), the watchdog timer, and two synchronous serial ports. The serial ports are configurable and double buffered, with hardware support for UART, SCI, and SPI port emulation. The ADMCF341 provides 512 24-bit program memory RAM, 4K 24-bit program memory ROM,4K 24-bit program FLASH memory, and 512 16-bit data memory RAM. The user code can be stored and executed from the flash memory. The program and data memory RAM can be used for dynamic data storage or can be loaded through the serial port from an external device as in other ADMCxxx family parts. The program memory ROM contains a monitor function as well as useful routines for erasing, programming, and verifying the flash memory.

The motor control peripherals of the ADMCF341 provide a 12-bit analog data acquisition system with six analog input channels with three dedicated ISENSE inputs (combining internal amplification, sampling, and overcurrent PWM shutdown features) and an internal voltage reference. In addition, a three- phase, 16-bit, center-based PWM generation unit can be usedto produce high accuracy PWM signals with minimal processor overhead. It also contains two 16-bit auxiliary PWM timer outputs and nine lines of digital I/O.

Because the ADMCF341 has a limited number of pins, functions such as the auxiliary PWM timers and the serial communication ports are multiplexed with the nine programmable digital input/ output (PIO) pins. The pin functions can be independently selected to allow maximum flexibility for di fferent applications.