Atmel Corporation

Srinivas Ramamurthy

Geoffrey S Gongwer

James Fahey

Neal Berger

Jinglun Eugene Tam

Eugene Jinglun Tam

William Saiki

William J Saiki

A JTAG Boundary Scan method by which the on-chip system logic (OCSL) of an integrated circuit is changed by use of a state machine which, among other functions, allows a predefined set of instructions to be loaded into an Instruction Register and then executed. The predefined instructions are designed to follow in sequence after certain other previous instructions. The instructions change the OCSL from one state to another state and allows the state to be changed without the need of a full device reset. Additional instructions within this invention were created to have attendant operating modes for which termination is self timed within the integrated circuit. Additional instructions further control the implementation of instruction execution within the state machine.

Boundary scan method for terminating or modifying integrated circuit

Boundary Scan integrated circuits are provided with a plurality of new registers between two dedicated pins, Test Data In (TDI) and Test Data Out (TDO) pins. The new registers include an address register and a plurality of test data registers which are addressable by the address register using address-dependent instructions in the instruction register (IR). Instructions for the addressable registers may be steered to the correct register with an ADDLOAD instruction placed in the instruction register followed by an address-dependent instruction. The ADDLOAD instruction makes the address register active between the TDI and TDO pins. Any instruction from a set of address-dependent instructions may be steered to any register handling address-dependent instructions allowing a small number of instructions to be used in a large number of addressable data registers. At the same time non-addressable registers, such as the Boundary Scan register, use address-independent instructions.

Boundary scan system with address dependent instructions

A boundary scan test circuit (JTAG) interface is used to provide data for a set of configuration latches within a Configuration Register. The Configuration Register is included within the JTAG structure as a Test Data Register (TDR). Each configuration bit within the Configuration Register consists of a Configuration Latch, and each configuration latch has an output used as a configuration control signal within an output logic macrocell. The configuration register's input signal is selectably provided from either a set of serially connected configuration bit non-volatile element sense latches or from the JTAG Test Data In (TDI) data pin for reconfiguration, prototyping, and testing.

Configuration control in a programmable logic device using non-volatile

Bulk operation logic circuitry for use in carrying out bulk program, erase, verify and margining operations on nonvolatile memory cells of a PLD, FPGA, flash-based microcontroller, EEPROM, flash memory device or other integrated circuit containing such cells includes a flag register for designating one or more selected blocks of cells to which the bulk operation will be limited. The bulk operation circuitry includes a controller, with a state machine and associated control logic, that distributes system clock signals and provides control signals to an instruction register, the flag register, an address register and one or more data registers to control loading of instructions and data into those registers through a serial input. The state machine is responsive to a mode signal for switching it from a normal user state into a bulk operation state. The use of a flag register allows simplification of the instruction set to register load instructions and basic bulk operation instructions (and a flow through operation using a serial output from the registers), while providing a wide variety of possible block selections for the different bulk operations.

Growing community of inventors

San Jose, CA, United States of America

Srinivas Ramamurthy