Texas Instruments Corporation

John W Hayn

Kevin C McDonough

Jeffrey D Bellay

Robert C Thaden

Michael J Hogan

A microcomputer device is disclosed containing a ROM for program memory, a read/write memory, and a CPU in a single integrated circuit. Input/output ports, interrupt and operating mode controls are memory mapped in the same logical address space as the program and read/write memory. The read/write memory is an array of one-transistor type dynamic storage cells in which data bits are stored in capacitor; refresh of this dynamic RAM is accomplished in a manner transparent to the CPU by an automatically-incremented address counter. Each data bit uses two one-transistor cells in a balanced, complementary array.

Microcomputer with automatic refresh of on-chip dynamic RAM transparent

An electronic digital processor system including an internal memory, an arithmetic and logic unit, registers, peripheral control circuitry providing an internal mode, an external mode, emulator mode, data paths, and control and timing circuitry. In the internal mode, the data and the commands are stored in the internal memory. In the external mode, the commands which control the operations of the microcomputer are stored in the external memory. In the emulator mode, the user can combine the microcomputer with external devices to emulate a composite system with minimal hardware. The emulator mode would also allow the user to develop software for the composite system.

Self-emulator microcomputer

A electronic digital processor system input/output circuitry including several input/output data ports where each port contains receiving circuitry to receive bit data from bit data pads and transmitting circuitry to transmit bit data to the data bit pads and control circuitry that provides for a configuration where one input/output port may respond to the address of another input/output port, allowing the second input/output port to perform other functions. This capability would allow a user to execute a program that emulates one configuration while the actual, physical connection of devices is, in fact, another configurations. The input/output circuitry also include control circuitry that determines whether the port is to receive bit data or to transmit bit data. This circuitry is connected to a data bus that couples the input/output data ports to the remaining electronic digital processor system.

Multiprogrammable input/output circuitry

A microcomputer device is disclosed containing a read-only memory for programs, a read/write memory usually containing data, and a CPU, all in a single integrated circuit. The CPU is microprogrammed in that each instruction word fetched from the program memory initiates a sequence of microinstructions to perform the operation defined by the instruction word. The sequence is determined by addresses for a control ROM, and the addresses are selected by a method referred to as dispatching. The control ROM output includes a jump address by which the next address may be any location in the entire control ROM address range. Alternatively, the jump address may be modified by any one of several dispatches. A group dispatch selects one of the modes of accessing source and/or destination operands, based on one field of the instruction word. A subsequent function dispatch selects one of the set of available arithmetic/logic operations to be performed in the CPU based on another field of the instruction word. Many of the microinstructions are shared by the various sequences; the opcode stays in the instruction register so it can be used for dispatch control even after many microinstruction states have been executed.

Shared microinstruction states in control ROM addressing for a

Microcomputer device using dispatch addressing of control ROM

A microcomputer device is disclosed containing a read-only memory for programs, a read/write memory usually containing data, and a CPU, all in a single integrated circuit. The CPU is microprogammed in that each instruction word fetched from the program memory initiates a sequence of microinstructions to perform the operation defined by the instruction word. The sequence is determined by addresses for a control ROM, and the addresses are selected by a method referred to as dispatching. The control ROM output includes a jump address by which the next address may be any location in the entire control ROM address range. Alternatively, the jump address may be modified by any one of several dispatches. A group dispatch selects one of the modes of accessing source and/or destination operands, based on one field of the instruction word. A subsequent function dispatch selects one of the set of available arithmetic/logic operations to be performed in the CPU based on another field of the instruction word. Many of the microinstructions are shared by the various sequences; the opcode stays in the instruction register so it can be used for dispatch control even after many microinstruction states have been executed.

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Houston, TX, United States of America

John W Hayn