ADSP-21990

The ADSP-21990 is a mixed signal DSP controller based on the ADSP-219x DSP Core, suitable for a variety of high performance Industrial Motor Control and Signal Processing applications that require the combination of a high performance DSP and the mixed signal integration of embedded control peripherals such as analog to digital conversion.

The ADSP-21990 integrates the 160 MIPS, fixed point ADSP-219x family base architecture with a serial port, an SPI compatible port, a DMA controller, three programmable timers, general purpose Programmable Flag pins, extensive interrupt capabilities, on chip program and data memory spaces, and a complete set of embedded control peripherals that permits fast motor control and signal processing in a highly integrated environment.

The ADSP-21990 architecture is code compatible with previous ADSP-217x based ADMCxxx products. Although the architectures are compatible, the ADSP-21990, with ADSP-219x architecture, has a number of enhancements over earlier architectures. The enhancements to computational units, data address generators, and program sequencer make the ADSP-21990 more flexible and easier to program than the previous ADSP-21xx embedded DSPs.

Indirect addressing options provide addressing flexibility-premodify with no update, pre- and post-modify by an immediate 8-bit, two's complement value and base address registers for easier implementation of circular buffering.

The ADSP-21990 integrates 8K words of on chip memory configured as 4K words (24-bit) of program RAM, and 4K words (16-bit) of data RAM.

Fabricated in a high speed, low power, CMOS process, the ADSP-21990 operates with a 6.25 ns instruction cycle time (160 MIPS). All instructions, except two multiword instructions, execute in a single DSP cycle.

The ADSP-21990's flexible architecture and comprehensive instruction set support multiple operations in parallel.

For example, in one processor cycle, the ADSP-21990 can:
• Generate an address for the next instruction fetch
• Fetch the next instruction
• Perform one or two data moves
• Update one or two data address pointers
• Perform a computational operation These operations take place while the processor continues to:
• Receive and transmit data through the serial port
• Receive or transmit data over the SPI port
• Access external memory through the external memory interface
• Decrement the timers
• Operate the embedded control peripherals (ADC, PWM, EIU, etc.)