Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data. An external program address bus allows the alternative of off-chip program fetch in each instruction cycle, with the opcode returned by an external data bus. Data I/O instructions for access to peripherals or external data memory use two machine cycles so that the external ROM fetch is not distributed. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances. The internal busses are 16-bit, while the ALU and accumulator are 32-bit. A multiplier circuit produces a single state 16.times.16 multiply function separate from the ALU, with 32-bit output to the ALU. One input to the ALU passes through a 0-to-15 bit shifter with sign extension.

Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data; however, the accumulator in the data path may be used as a program address source for table look-up for accumulator addressing, for example. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. The on-chip program memory may be disabled and only off-chip memory used for program fetch in a systems emulator mode. A non-maskable interrupt procedure used in the emulator mode generates a vector address for the on-chip ROM in switching between memory expansion and emulator modes, using an overvoltage detector to signal this condition.

Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data; however, the accumulator in the data path may be used as a program address source for table-read and table-write, for example. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances, such as accumulator addressing. The internal busses are 16-bit, while the ALU and accumulator are 32-bit. A multiplier circuit produces a single state 16.times.16 multiply function separate from the ALU, with 32-bit output to the ALU. One input to the ALU passes through a 0-to-15 bit shifter with sign extension.

Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program and data. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances; for example, the internal program ROM may be read out on the data bus, one opcode at a time for test purposes, without executing the opcodes.

Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances. The internal busses are 16-bit, while the ALU and accumulator are 32-bit. A multiplier circuit produces a single state 16.times.16 multiply function separate from the ALU, with 32-bit output to the ALU. One input to the ALU passes through a 0-to-15 bit shifter with sign extension.

Abstract: A system for real-time digital signal processing employs a single-chip microcomputer device having separate on-chip program ROM and data RAM, with separate address and data paths for program and data. An external program address bus allows off-chip program fetch in an expansion mode, with the opcode returned by an external data bus. A bus interchange module allows transfer between the separate internal program and data busses in special circumstances. The internal busses are 16-bit, while the ALU and accumulator are 32-bit. A multiplier circuit produces a single state 16.times.16 multiply function separate from the ALU, with 32-bit output to the ALU. One input to the ALU passes through a 0-to-15 bit shifter with sign extension. The data RAM has an internal shift arrangement useful in processing convolution algorithms. An addressed location in the RAM is read out and also shifted to the next higher location in one instruction cycle.