Thomson Semiconducteurs

Thomson Composants Militaires Et Spatiaux

Thomson Composants Militaires & Spaciaux

Alexis Marquot

Serge Fruhauf

An integrated circuit of the logic circuit type comprises an electrically programmable non-volatile memory formed by a matrix of memory cells of the floating-gate transistor type, with read and write circuits handling the interconnection of these circuits with the memory, the integrated circuit receiving a general power voltage V.sub.CC and a programming voltage V.sub.pp which are different from one another. The circuit can also detect the main power voltage V.sub.CC, sending a signal to prohibit writing in the memory when it is observed that the power voltage V.sub.CC is at zero or in high impedance while thep rogramming voltage is present.

Integrated circuit of the logic circuit type comprising an electrically

An electrically programmable non-volatile memory includes a matrix of memory cells accessible by rows and columns, write and read circuits which apply potentials, representing the programmed datum or representing the read command, to the rows and columns. The memory also includes a device which controls the interconnection of the write and read circuits with the memory cells, wherein N memory cells are programmed simultaneously, N being greater than 1, each memory cell setting up a current surge when it is programmed at '1'. The memory also includes a device for deactivating, one by one, the write circuits corresponding to the N memory cells where there is a change-over from a programming mode to a read mode, and a structure to short-circuit the deactivation device at the change-over to the programming mode.

Electrically programmable non-volatile memory having sequentially

An integrated circuit of the logic circuit type includes a matrix of memory cells of the floating-gate transistor type, write and read circuits and circuitry to handle the interconnection of these circuits with the memory. The integrated circuit receives a general supply voltage Vcc, a programming voltage Vpp and an external clock signal divided into two complementary clock signals. The clock signals acts on, among others, the functioning of the write circuits. The integrated circuit further includes a circuit to detect the presence of internal clock signals. The circuit sends a signal prohibiting write operations in the memory when it detects the absence of one of the internal clock signals.

In a memory consisting of a matrix of memory cells, each of which is accessible by rows and columns and is connected to write and read circuits which are used, respectively, to programme them in two states, '1' or '0', depending on the input data, and to read the programmed state, the memory cells being of the type that require a programming current in order to be programmed in a first state or '1' and require no current to be programmed in a second state or '0', the safety device consists of a simulation circuit activated by data corresponding to a '0' programming operation and delivering a current identical to that of a memory cell in the '1' programming condition.

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St Maximin, France

Alexis Marquot