Abstract:
A circuit (165) is proposed for controlling a reference node (Nr) in a sense amplifier (145) switchable between an operative condition and a stand-by condition, the reference node providing a reference voltage in the operative condition. The circuit includes means (Cp) for bringing the reference node to a starting voltage upon entry into the stand-by condition, first means (Rda1,Rda2) for keeping the reference node at a pre-charging voltage in the stand-by condition, second means (Rdb1,Rdb2) for providing a comparison voltage closer to the pre-charging voltage than the starting voltage, pulling means (Mu1) for pulling the reference node towards a power supply voltage, and control means (210) for activating the pulling means upon entry into the stand-by condition and for disabling the pulling means when the voltage at the reference node reaches the comparison voltage.
Abstract:
A redundancy architecture for a memory wherein the array of memory cells is divided in at least a pair of banks or semiarrays (EVEN_BANK, ODD_BANK) singularly addressable (ADDR_latch_E, ADDR_latch_O), organized in rows and columns; the architecture comprising a certain number of packets each composed of a certain number of redundancy columns of cells (REDUNDANCY), contemplates dividing said number of packets (REDUNDANCY) in two subsets of packets (REDUNDANCY_EVEN, REDUNDANCY_ODD), each one addressable independently from the other by way of respective address circuits and providing redundancy columns of cells exclusively for a respective bank or semiarray (EVEN_BANK, ODD_BANK).
Abstract:
A pre-charging circuit of the output node of an output buffer (BUFFOUT) of an integrated digital system generating at least a first pulse (DLATCHN) for enabling the external visibility of a new datum (DATA) and a second pulse (LOAD) having a shorter duration than the first pulse (DLATCHN) for loading the new datum (DATA) in an output data register (DATABUS_LATCH) whose output is coupled to the input of said output buffer (BUFFOUT) , includes a capacitor (INTERNAL_CAPACITOR) connectable in parallel to the load capacitance of the output node ( IO_pad ) of the buffer by means of a second pass-gate enabled by a pre-charge command (PRECHARGE) corresponding to the logic AND of said second pulse (LOAD) and of the logic XOR of the new datum (DATA) and of the datum (OUT) currently present on the output node ( IO_pad ), and a driver (D) , disabled by said enabling first pulse (DLATCHN) charging said capacitor (INTERNAL_CAPACITOR) to a voltage (VC) corresponding to the logic level of a datum belonging to the group composed of said new datum (DATA) and the logic inversion of the current datum (OUT).
Abstract:
A method of synchronizing the start of sequential read cycles when reading data in a memory in a synchronous mode with sequential access, using the increment pulses for at least an address counter of the memory cell array as synchronization signals, by generating, following each increment pulse, a dummy ATD pulse, undistinguishable from an ATD pulse generated upon detection of a switching of external address lines.
Abstract:
An interleaved memory readable in sequential access synchronous mode and in random access asynchronous mode, in function of external protocol signals ( ALE; CEn, RD ), has a circuit of internal regeneration of an external input address latch enabling signal ( ALE ), filtered by a second external chip enable signal ( CEn ). The circuit comprises a latch ( LATCH ) storing the external signal ( ALE_EXT ) of input address latch enabling and a NOR gate combining the output ( ALE_BUFF ) of the latch with the second external signal of chip enable ( CEn ) and producing a first internal replica signal of address latch enabling ( ALE_FAST ). Delay circuits in cascade to the output of the latch and in cascade of the input pad of the external signal of chip enable ( CEn ) and logic means combining the internally generated replica signal ( ALE_FAST ) and the signal ( ALE_BUFF ) present at the output of the latch with signals retarded by said delay circuits produce set and reset signals of an output flip-flop outputting a second internally generated reconditioned address latch enabling signal ( ALE ). The reconditioned signal has a raising edge conditionally retarded compared to the raising edge of the external command ( ALE_EXT ) and a duration that is conditionally incremented such to compensate for eventual critical asynchronisms between the two protocol external signals ( ALE_EXT, CEn ) in the different modes of operation of the interleaved memory.
Abstract:
An address binary counter for a subdivision bank of the cell array of an interleaved memory with burst access enabled by an enabling signal (ENABLE), comprises as many stages as the bits that may be stored in the cells of a row of the bank and a carry calculation network. The carry calculation network comprises an ordered group of independent carry generators, each of a certain number of stages, and having its own enabling bit, that are input with a number of consecutive bits of a row of the bank equal to the number of stages, orderly starting from the least significant bit. The enabling bit of the first carry generator of the ordered group is said enabling signal (ENABLE), and the enabling bit of any other carry generator of the ordered group is the logic AND of said enabling signal and of the input bits of the preceding carry generator of the ordered group.
Abstract:
The transfer of data within a system having a plurality of data sources (ASYNC BLOCK asynchronous and/or having different bitrates, to produce an output data stream (OUT) synchronous with a certain external timing signal (CLOCK, RD) of request of updating of the datum currently present at the output, is managed by a circuit that includes an output register (OUT REG) in which the datum to be made available at the output is stored and at least an output buffer (OUT BUFF) driving an external data line and functionally coupled to the output of said output register (OUT REG). Each data source (ASYN_BLOCK ) has a data loading register (REG ), a selection multiplexer (MUX) of data to be transferred from one or another of said loading registers to said output register (OUT REG). A central control unit (CPU) produces a plurality of control signals (START , REQ , PRIORITY , CLOCK, RD, GLOBAL_RESET). The circuit managing the transfer (SYNC_ASYN CONTROL) includes a plurality of identical circuits, each dedicated to one of said data sources and composed of a coincidence detecting circuit with hooking (COINCIDENCE DETECTOR WITH HOOKING) input with the logic end signal (PULSE) of said external timing signal (CLOCK RD) and of a selection signal (REQ ) of the source of the datum to be produced in output, and a confirmation signal (DATA_READY ) of availability of the datum at the output of said selected source, outputting in a stretching signal (OK_STR), and of a conditioned update path of the output datum constituted by a first bistable circuit (LATCH UPDATE FLAG) set by the inverted confirmation signal (DATA_READY ) and reset by the logic OR of a global reset command (GLOBAL_RESET) generated by the central control unit (CPU) and of the logic OR of the timing signal (CLOCK) and of the stretching signal (OK_STR), outputting a first flag (OK_UPDATE) of enablement of the updating; a second bistable circuit (ENABLING FLAG OF OUT REG UPDATE) set by the output of said detecting circuit and reset by the logic OR of the signal (GLOBAL_RESET) and of a signal (NEW_OUT) corresponding to the logic OR of signals (NEW_OUT ) coming from the respective data sources , outputting an update flag (PRE_LOAD); a logic OR gate, input with the update flag (PRE-LOAD) and with the logic OR signal of the signal (PULSE) and of the stretching signal (OK_STR) and producing in output a selection signal (LOAD ) for the multiplexer (MUX); a pass-gate coupling the input of an output buffer OUT BUFF to the respective output register OUT REG, enabled by the logic OR signal (NEW_OUT) of the signals (NEW_OUT ), each corresponding to the logic OR of the signal (PULSE) and of the stretching signal (OK_STR) of the managing circuit (block ) of a respective data source.