The Z89320 is a second generation, 16-bit fractional, two's complement CMOS Digital Signal Processor (DSP). Most instructions, including multiply and accumulate, are accomplished in a single clock cycle. The processor contains 1Kbyte of on-chip data RAM (two blocks of 256 16-bit words), 4K words of program ROM. Also, the processor features a 24-bit ALU, a 16x16 multiplier, a 24bit Accumulator and a shifter. Additionally, the processor contains a six-level stack, three vectored interrupts and two inputs for conditional program jumps. Each RAM block contains a set of three pointers which may be incremented or decremented automatically to affect hardware looping without software overhead. The data RAMs can be simultaneously addressed and loaded to the multiplier for a true single cycle multiply.