US 5,844,843 A · Single chip data processing apparatus having a flash memory which is rewritable under the control of built-in CPU in the external write mode

Abstract

A single chip data processing apparatus having a central processing unit (CPU) and a flash memory constituted by electrically rewritable nonvolatile memory cells. The flash memory can be written with data under the control of the built-in CPU in an external write operation mode of the apparatus and, also, the CPU executes a data processing operation in accordance with a data processing program in a normal operation mode. In the external write operation mode, the CPU decodes a command by executing a command analyzing program so as to determine a process to be performed to the flash memory. Based on the decoding result of the command, the CPU executes a control program for performing the process to the flash memory, which process can be changing threshold voltages of selected nonvolatile memory cells of the flash memory to predetermined threshold voltages or verifying whether or not the threshold voltages of selected ones of the nonvolatile memory cells of the flash memory have been changed to predetermined threshold voltages. The data processing apparatus also has a built-in command latch circuit, an address latch circuit as well as a data latch circuit such that the CPU reads the command latched in the command latch circuit and decodes the command by executing the command analyzing program and, also, performs the process to the flash memory on the basis of the address latched in the address latch circuit and the data latched in the data latch circuit.

Claims34

Dependent claims

A data processing apparatus on a single semiconductor substrate, the data processing apparatus having a first mode and a second mode, comprising:

external terminals which receive commands in the second mode;
a flash memory including a plurality of electrically rewritable nonvolatile memory cells each of which is constructed of a single transistor, the flash memory being written with data in the second mode;
and
a central processing unit which executes a data processing operation in accordance with a data processing program in the first mode and which decodes in the second mode a command by executing a command analyzing program so as to determine a process to be performed to the flash memory, the central processing unit being responsive to the decoding result of the command and controlling operations of the flash memory by executing a control program for performing the process, which process is for changing threshold voltages of ones of the plurality of electrically rewritable nonvolatile memory cells to predetermined threshold voltages or for verifying whether or not threshold voltages of ones of the plurality of electrically rewritable. nonvolatile memory cells have been changed to predetermined threshold voltages.

1 more element

A data processing apparatus on a single semiconductor substrate, the data processing apparatus having a normal operation mode and an external write operation mode, comprising:

external terminals which receive commands in the external write operation mode;
a flash memory which stores a command analyzing program, a control program and a predetermined program and being writable with data in the external write operation mode,
wherein the flash memory includes a plurality of electrically rewritable nonvolatile memory cells each of which is constructed of a single transistor;
a random access memory which stores the command analyzing program and the control program provided from the flash memory in the external write operation mode;
and
a central processing unit which executes the predetermined program in the normal operation mode and which decodes in the external write operation mode a command by executing the command analyzing program in the random access memory so as to determine a process to be performed to the flash memory, the central processing unit being responsive to the decoding result of the command and controlling operations of the flash memory by executing the control program in the random access memory for performing the process, which process is for changing threshold voltages of ones of the plurality of electrically rewritable nonvolatile memory cells to predetermined threshold voltages or for verifying whether or not threshold voltages of ones of the plurality of electrically rewritable nonvolatile memory cells have been changed to predetermined threshold voltages.

3 more elements

A data processing apparatus on a single semiconductor substrate, comprising:

a flash memory;
a central processing unit executing a command analyzing program for decoding a command supplied from outside of the data processing apparatus in a first mode so as to determine a process to be performed to the flash memory, the central processing unit being responsive to a decoding result of the command and controlling operations of the flash memory by executing an erasure program and/or a write program so as to perform the process.

Dependencies are inferred from the claim text.

Single chip data processing apparatus having a flash memory which is rewritable under the control of built-in CPU in the external write mode

Life of this patent

Single chip data processing apparatus having a flash memory which is rewritable under the control of built-in CPU in the external write mode

Life of this patent

Abstract

Claims34