Abstract: The invention includes an apparatus and method of selecting memory cells within a memory array. The method includes receiving a memory cell address. A column address and a row address are generated from the memory cell address. Row select lines or column select lines are pre-charged. A self-timed charging circuit is initiated to provide an adequate amount of time to charge a selected row, and to initiate elimination of static current flowing to unselected rows after a self-timed delay. The other of the row select lines or the column select lines are then pre-charged. Memory cells are selected based upon the column address and the row address. One of two states of the memory cells can be based upon sensing threshold voltages of sense lines that correspond with the selected memory cells.

Abstract: An auxiliary voltage generation circuit is part of a high voltage generation and regulation circuit. The auxiliary voltage generation circuit generates an auxiliary intermediate voltage that is coupled to a negative level shifting circuit to reduce the drain-source stress experienced by transistors in that circuit that are in an off state. The auxiliary voltage generation circuit also generates a logic control signal that indicates to a high voltage discharge path to perform either a slow discharge operation or a fast discharge operation.

Abstract: The present invention provides a sense circuit for DRAM memory cell to cover the events that a sense time becomes remarkably longer when a power source voltage is lowered, a sense time under the low voltage condition becomes shorter when temperature rises and a sense time changes to a large extent for fluctuation of processes. The present invention provides the following typical effects. A switch means is provided between the bit line BL and local bit line LBL connected to the memory cells for isolation and coupling of these bit lines. The bit line BL is precharged to the voltage of VDL/2, while the local bit line LBL is precharged to the voltage of VDL. The VDL is the maximum amplitude voltage of the bit line BL. A sense amplifier SA comprises a first circuit including a differential MOS pair having the gate connected to the bit line BL and a second circuit connected to the local bit line LBL for full amplitude amplification and for holding the data.

Abstract: A memory sense amplifier includes a sample and hold circuit followed by a differential amplifier. The sample and hold circuit samples a reference voltage on a bit line of a memory circuit when the sense amplifier is reset and a signal voltage on the same bit line when a signal representing a data bit is present in the bit line. The differential amplifier amplifies the difference between the signal voltage and the reference voltage.

Abstract: For one disclosed embodiment, an apparatus comprises a first p-type device coupled between a cell voltage node and a storage node, an n-type device coupled between the storage node and a reference voltage node, and a second p-type device to couple the storage node to a bit line in response to a signal on a select line. At least one side of diffusion regions in a substrate to form both the first p-type device and the second p-type device are substantially aligned. Other embodiments are also disclosed.

Abstract: A switched capacitor sense amplifier includes capacitively coupled input, feedback, and reset paths to provide immunity to the mismatches in transistor characteristics and offsets. The sense amplifier includes a cross-coupled pair of inverters with capacitors absorbing offset voltages developed as effects of the mismatches. When used in a dynamic random access memory (DRAM) device, this immunity to the mismatches and offsets allows the sense amplifier to reliably detect and refresh small signals.

Abstract: An equalization circuit for a pair of resistive-capacitive data lines includes primary and secondary equalization circuits attached at both ends of the data line pair. A primary equalization circuit at one end of the data line pair receives a primary control signal, and a secondary equalization circuit at the other end of the data line pair receives a secondary control signal, which is different than the primary control signal. The equalization devices in the primary equalization circuit are attached near the read and write amplifiers and operate normally since all the information is available as to whether or not the corresponding data line pair should be equalized. The additional equalization devices in the secondary equalization circuit placed at the other end of the data line pair receive a simpler control signal that lacks the information as to whether or not any particular data line pair is being equalized.

Abstract: A Radio-Frequency Identification (RFID) transponder is provided. The RFID transponder may include a basic ID flag circuit having a VDD voltage node, an output voltage node, and a capacitor coupled to the VDD voltage node and the output voltage node to store an ID flag. A supplemental discharge current circuit coupled to the basic ID flag circuit is provided in order to control persistence duration of the state of the ID flag. The persistence duration of the state of the ID flag is controlled by maintaining supplemental discharge current, which is greater than the leakage current of the basic ID flag circuit.

Abstract: A memory includes a selected bitline coupled to the array of memory cells. A column multiplexer passes a signal on the selected bitline to a sense amplifier input in response to a column enable signal. A multiplexer output conditioner discharges the sense amplifier input and a bitline conditioner precharges and readjusts the selected bitline to a precharge threshold. A sense amplifier produces a data output that is based on the sense amplifier input.

Abstract: In a data reading method, a first reading pulse is applied to a memory cell to generate a first signal corresponding to data stored in the memory cell, reference signal generating data corresponding to a high level side is written to the memory cell, a second reading pulse is applied to the memory cell to generate a second signal corresponding to the reference signal generating data, and a reference signal is generated on the basis of the second signal. Then the first signal and the reference signal are compared with each other to determine the stored data stored in the memory cell. In data writing, high-level data is written to the memory cell without using a bit line.

Abstract: A semiconductor storage device having a word line driving circuit of a small circuit scale, and operating in stability. The device includes a first driving circuit 11 for driving a word line driving signal 15 towards a first potential, a second driving circuit 12 for driving the word line driving signal 15 towards a second potential, a third driving circuit 13 for driving the word line driving signal 15 to a third potential, and a driving control circuit 14. This driving control circuit 14 actuates the first driving circuit 11 when the input signal 16 is at a first logical value, while actuating the second driving circuit 12 when the input signal 16 transfers from the first logical value to the second logical value and actuating the third driving circuit 13 on detection that the word line driving signal 15 has been driven towards the second potential.

Abstract: Dual match line circuits having race condition improvements. A dual match line circuit may include precharge logic configured to precharge each of a hit match line, a miss match line and an evaluate node to an asserted state, where a coupling device couples the hit and miss match lines to the evaluate node. The miss match line may discharge through a number of load devices that may be activated by respective miss signals. A positive feedback circuit coupled to the miss match line may accelerate its discharge. The hit match line may be additionally coupled to discharge through a discharge path. The hit and miss match lines may be electrically isolated from one another, such that when any of the respective miss signals is asserted, current from the hit match line does not discharge through the miss match line.

Abstract: A dual match line circuit may include precharge logic configured to precharge each of a hit match line, a miss match line and an evaluate node to an asserted state, where a coupling device couples the hit and miss match lines to the evaluate node. The miss match line may discharge through a number of load devices that may be activated by respective miss signals. The hit match line may be additionally coupled to discharge through a pair of devices connected in series, one of which may be activated by a hit signal, and the other of which may be activated by the miss match line. The hit and miss match lines may be electrically isolated from one another, such that when any of the respective miss signals is asserted, current from the hit match line does not discharge through the miss match line.

Abstract: An erase discharge circuit in a flash memory is coupled to an array source and a p-well drive and receives first and second discharge signals. The erase discharge circuit operates during a discharge cycle in a first mode in response to the first discharge signal to couple the first node to the second node and to discharge voltages on the first and second nodes at a first rate. The erase discharge circuit operates in a second mode in response to the second discharge signal to couple the first node to the second node to discharge the voltages on the first and second nodes at a second rate.

Abstract: A memory access method and a memory system are disclosed for shortening a memory cell access time. The memory system comprises one or more memory cells, at least one bit-line discharge subsystem having one or more discharge modules, each discharge module coupled to a bit-line connecting to one or more memory cells for discharging a voltage level of the bit-line upon a triggering of a discharge control signal, at least one sense amplifier coupled to the bit-line for determining data stored in a selected memory cell, at least one latch module for storing the determined data from the sense amplifier upon a triggering of a latch enable signal, wherein the discharge control signal is triggered prior to the triggering of the latch enable signal so that the voltage level of the bit-line is discharged for allowing an accelerated reading of the data.

Abstract: A plasma damage protection circuit includes a word line driver circuit with plasma damage protection features. If, during manufacture, plasma-based processes cause charge to build up on the word lines, the charge passes from the word lines through at least the word line drivers to the semiconductor substrate. Another plasma-based protection circuit includes a device coupled to multiple word line drivers. If, during manufacture, plasma-based processes cause charge to build up on the word lines, the charge passes from the word lines through at least the device to the semiconductor substrate. Thus, these plasma-based protection circuits save space while protecting the integrated circuit from plasma process-based damage.

Abstract: An integrated circuit includes a memory (10). The memory (10) includes an array (12) of non-volatile memory cells. Each memory cell (14) of the array (12) includes a plurality of terminals comprising: a control gate, a charge storage region, a source, a drain, a well terminal, and a deep well terminal. Following an erase operation of the array (12), the erase voltages are discharged from each of the memory cells. A discharge rate control circuit (11) controls the discharging of terminals of the memory cell. The discharge rate control circuit (11) includes a reference current generator (34) for providing a reference current. A first current mirror (46) is coupled to the reference current generator (34) and provides a first predetermined discharge current for discharging the control gate, drain, and source. A second current mirror (36) is coupled to the reference current generator (34) and provides a second predetermined discharge current for discharging the well terminals after the erase operation.

Abstract: One or more external control pins and/or addressing pins on a memory device are used to set one or both of a burst length and burst type of the memory device.

Abstract: A technique to pre-charge a CAM block array including a plurality of CAM blocks that is organized into at least one rectangular array having rows each having a plurality of CAM blocks, an associated GMAT line, an associated LMAT line, and a group of CAM cells. The pre-charge technique of the present invention accommodates for all CAM block configurations without compromising performance at the cost of silicon area. In one example embodiment, this is accomplished by precharging each LMAT line in the CAM block array. A predetermined amount of delay is then applied substantially after precharging each LMAT line. Each GMAT line in the CAM block array is then precharged.

Abstract: A memory device in accordance with embodiments of the present invention includes a reference cell array and a plurality of banks. Each of the banks includes memory cells. A plurality of current copier circuits corresponds to the banks, respectively. Each of the current copier circuits copies a reference current flowing through a reference cell array to generate a reference voltage. A plurality of sense blocks correspond to the banks, respectively. Each of the sense blocks includes a plurality of sense amplifiers for sensing data from a corresponding bank in response to the reference voltage from the corresponding current copier circuit. Memory cell lay-out area is reduced, and sense speed is increased.

Abstract: A memory cell includes first and second data holding portions for holding stored data and its inverted data. First and second p channel TFT compensate for charges leaked from first and second capacitors, respectively. A first (second) access transistor has first and second gate electrodes connected to a first (second) word line and to a second (first) node, respectively. The first (second) access transistor discharges the charges leaked from a power supply node via the first (second) p channel TFT in the OFF state in the leakage mode where the first (second) word line is inactivated and the second (first) node is at an H level.

Abstract: It is intended to provide a control method of a semiconductor memory device and a semiconductor memory device capable of shortening pre-charge operation time that comes after termination of successive data access operation, namely, successive data read/write operation, without causing deterioration of restore voltage to memory cells and delay of initial data access time. An activated word line WL0 is deactivated with appropriate timing that is between time after bit line pairs (BL0 and /BL0, . . . BLN and /BLN) are differentially amplified up to full amplitude voltage level and time where column selecting lines CL0, . . . CLN are selected. That is, deactivation time ?A for the word line can be embedded in a period of successive data access operation. Pre-charge operation can be terminated within time that is a sum of deactivation time ?B of a sense amplifier and equalizing time ?C of the bit line pairs. Thereby, pre-charge period can be shortened.

Abstract: A method and circuit for refreshing dynamic memory cells arranged along word lines and bit lines are provided, the memory cells being refreshed in a manner dependent on a refresh signal with a refresh frequency by the activation of the word line in order to write the information back to the memory cells arranged on the relevant word line, in which case the refresh frequency is set in a manner dependent on the charge loss of first dummy memory cells during a refresh period of the refresh signal on a first dummy word line and/or in a manner dependent on the charge loss of second dummy memory cells during the refresh period of the refresh signal on a second dummy word line.

Abstract: A random access memory (RAM), such as a dynamic RAM (DRAM) or embedded DRAM (eDRAM) on a CMOS integrated circuit (IC) logic chip. Memory banks drive one line of a connected global data line pair to develop a difference signal on the pair. Simultaneously, a global signal monitor line discharges to develop a signal that mirrors the signal developing on one of the pair. When the global signal monitor line discharges sufficiently to indicate that the difference signal is large enough to sense, a global sense control sets a global data sense amplifier, the memory banks drive shuts off, and the global sense control initiates restoring global data line.

Abstract: A content addressable memory (CAM) device (200) can equalize a potential between a match line (202) and corresponding pseudo-supply (PVSS) line (204) in a pre-sense operation. In a sense operation, a sensing device (P4) can determine a match condition exists when the match line (202) potential varies from the PVSS line (204) potential. Complementary compare data lines (CD and BCD) can be equalized with one another in a pre-sense operation, while one compare data line (CD or BCD) can be equalized with bit lines (BB1 and/or BB2) in the sensing operation.

Abstract: In a ROM structure, power consumption is reduced by providing for pre-discharging of only the bit line corresponding to the memory location that is being read. Column select lines are coupled to logic to switch in a pre-discharging circuit prior to reading, and to disconnect, from the pre-discharging circuit during reading, only the bit line corresponding to the memory location being read.

Abstract: DRAM memory device (1) comprising at least one array of memory cells (2, 3, 4, 5), each memory cell (12) being connected to a bit line (BL) and a word line (WL), each of said bit lines (BL) being connected to a sense amplifier and a pre-charge circuit (15); a controllable active-current generator (7, 8, 9, 10) for providing power to the sense amplifiers and pre-charge circuits (15) for a time interval that is limited by a time at which a command for a read or write access is applied to the DRAM memory device (1) and an assigned switching time; a controllable standby-current generator (6) for providing power to the sense amplifiers and pre-charge circuits (15) after the switching time; a control circuit (11) for receiving external data, address and control signals (C, A, D) and for controlling the active-current generator (7, 8, 9, 10) and the standby-current generator (6); wherein the control circuit (11) is adapted to control the time for switching the respective power generator (6, 7, 8, 9, 10) to the sense

Abstract: A method and apparatus for discharging global bitlines in a flash memory to a voltage sufficiently low to avoid drain disturb for non-selected cells in a programming operation. A discharge device allows discharge of global bitlines coupled to local bitlines before a programming operation.

Abstract: A Radio-Frequency Identification (RFID) transponder is provided. The RFID transponder may include a basic ID flag circuit having a VDD voltage node, an output voltage node, and a capacitor coupled to the VDD voltage node and the output voltage node to store an ID flag. The persistence duration of the state of the ID flag is controlled by maintaining a charge and leakage circuit. The charge and leakage circuit includes an NMOS device having a source, a drain and a gate, the source node of the NMOS device being coupled to the capacitor and the drain node of the NMOS device being coupled to a first CMOS inverter. The first CMOS inverter is powered by a regulated supply voltage such that the voltage on the capacitor is not dependent on the forward voltage drop of the NMOS device.

Abstract: An electronic memory device includes at least one memory cell, a write circuit that defines an output node and mediates a discharge associated with a write operation flowing to the output node, and a write strength selection circuit that modifies at least one characteristic of the discharge. A method for testing data retention of an electronic memory device includes providing a write circuit, storing a value in at least one memory cell of the memory device, directing a weak write operation to the at least one memory cell, and sensing the memory cell to determine if the stored value changed in response to the weak write operation.

Abstract: The invention may comprise circuit for programmable control of a discharge deactivation signal when interfacing local bitlines to a global bitline or other circuit. The invention may also comprise a method for programmable ground circuit control for control of a discharge signal deactivation when interfacing local bitlines to a global bitline via a bitline evaluation discharge device comprising: providing input logic states to inputs of a controller circuit; outputting an adjustable ground value from the controller circuit; and controlling the bitline evaluation discharge device with the adjustable ground value.

Abstract: A memory system includes storage cells, a respective one of which is configured to store a fixed charge therein when a write voltage applied thereto is above a predetermined threshold voltage and to discharge the fixed charge therefrom when the write voltage applied thereto is below the threshold voltage. The storage cells may be charged and/or discharged at a latency that is a function of a voltage differential between the write voltage and the threshold voltage. A variable-latency write circuit for the storage cells is configured to dynamically vary the voltage differential between the write voltage and the threshold voltage to provide a variable-latency write operation that stores the fixed charge therein or discharges the fixed charge therefrom. Related methods are also discussed.

Abstract: There is provided a semiconductor memory device capable of performing high-speed reading even when the current capability of memory cells and transistors for charging is decreased, and a bit line capacitance is increased. In a sense amplifier, in addition to a P-type MOS transistor for charging, a P-type MOS transistor and a N-type MOS transistor are provided as a circuit for charging a selected bit line up to a switching level of a determination inverter included in a circuit for determining data of a memory cell, and a bit line is charged at high speed, whereby a read time is shortened.

Abstract: A row driver circuit receives a supply voltage and operates to develop a boosted voltage having a magnitude that is equal to the sum of an incremental boost voltage and a magnitude of the supply voltage. The magnitude of the incremental boost voltage is a function of the magnitude of the supply voltage to maintain the boosted voltage at an approximately constant value independent of variations in the supply voltage. A method of generating a boosted voltage includes detecting a value of a supply voltage, generating an incremental boost voltage having a value that is a function of the detected supply voltage, and adding the generated incremental boost voltage to the supply voltage to generate the boosted voltage.

Abstract: A delayed bitline leakage compensation circuit for memory devices is disclosed. The delayed bitline leakage compensation circuit includes a bitline leakage model circuit for modeling discharge of a bitline by leakage current in a read operation. It further has a delayed charge signal generator for generating a delayed charge signal in response to the bitline leakage model circuit discharging to approximately a discharge threshold. The delayed charge signal generator is deactivated if the bitline is discharged by a selected memory cell. Moreover, the delayed bitline leakage compensation circuit includes a delayed charge circuit for charging the bitline in response to the delayed charge signal.

Abstract: A semiconductor memory device is characterized by including a bit line, a transistor coupled to the bit line, a ferroelectric memory cell coupled to the bit line via the transistor, a shift circuit coupled to the bit line to lower a data potential that appears on the bit line in response to data stored in the memory cell, and a sense amplifier coupled to the bit line and to a ground potential to amplify a potential difference between the data potential lowered by the shift circuit and the ground potential.

Abstract: Voltage coupling/decoupling devices are provided within DRAM devices for improving the bias sensing of sense amplifiers and thus the refresh performance. The voltage coupling/decoupling devices couple or decouple bias voltage from corresponding digit lines coupled to the sense amplifiers. By coupling and decoupling voltage from the digit lines, the time interval between refresh operations can be increased.

Abstract: An internal voltage generating circuit in a semiconductor memory device includes a comparing unit for comparing a voltage level of an internal voltage with that of a reference voltage, a pull-up driving unit for performing a pull-up operation for an output terminal in response to an output signal of the comparing unit, and a discharging unit for discharging the output terminal in a period of which the voltage level of the internal voltage is higher than a predetermined target voltage level.

Abstract: In a SRAM structure, power consumption is reduced by providing a structure which allows specific memory cells to be selected using word lines and column select lines, and reducing the load on the column address lines by dividing the load into sectors. The dividing into sectors is achieved by making use of sector select lines for selecting two or more rows of cells, and logically ANDing the sector select lines with the column select lines.

Abstract: A semiconductor memory storage is disclosed, in which the gate of each of a plurality of n-channel transistors is connected to the corresponding one of a plurality of word lines on the output side of each word line driver. The source of the n-channel transistor is connected through a selective switching element to the gate of the corresponding one of a plurality of replica transistors connected to a dummy bit line. The gate of each replica transistor is connected to the corresponding one of discharge transistors. The dummy bit line is connected to a sense amplifier through a logic gate.

Abstract: An integrated circuit includes a memory, and the memory includes a memory plane arranged in rows and columns, and a plurality of read amplifiers connected to the columns of the memory plane. A reference path includes first and second reference columns, and a reference memory cell is connected between the first and second reference columns. A reference row is connected to the reference memory cell for selection thereof so that the first reference column conducts a discharge current and the second reference column conducts a leakage current. A control circuit is connected between the first and second reference columns and the read amplifiers. The control circuit provides an activation signal to the read amplifiers when an absolute value of a difference between voltages on the first and second reference columns exceeds a threshold.

Abstract: A low-power, compilable memory uses a charging pulse technique to improve access times over other low-power memory implementations. The memory includes circuitry configured to discharge a plurality of bit lines during an inactive memory access period to reduce power consumption. The memory also includes other circuitry that applies a charging pulse during an active memory access period on a select one of the plurality of bit lines in order to improve the memory access times. An automatic memory compiler adjusts a timing circuit to control the duration of the charging pulse and the enabling of a sense amplifier circuit during memory design. The memory compiler provides a programmable physical size of the memory and optimizes the access timing while ensuring reliable sensing. The compiler calculates timing for the timing circuit according to a mathematical formula that provides for highly accurate and predicable access time delays for multiple memory configurations.

Abstract: Circuitry and methods are provided for controlling memory operation by comparing bit line voltages to preset reference voltages. By relying on bit line voltage levels to determine when to start and end each stage of a read or write operation, reliance on precisely tuned delay chains is removed. Parasitic effects are automatically accounted for, as well as process, voltage, and temperature variations. This precise matching of operation timing to memory bit line conditions results in improved system performance.

Abstract: A Content Addressable Memory device with a bit line that is driven between first and second voltage levels depending on the state of a logic signal applied thereto. The magnitude of the voltage swing between the first and second voltage levels is reduced in comparison to other voltages of the Content Addressable Memory device, or in comparison to the voltage swing of prior art bit lines, so that effects associated with power dissipation by the bit line are reduced. The memory includes a plurality of match lines and a plurality of bit lines, each of the plurality of bit lines coupled to a bit line driver circuit adapted to provide a bit line voltage with reduced signal swing.

Abstract: A sense amplifier (11) and method for sensing a MRAM cell (77) is provided. The sense amplifier (11) includes a precharge circuit (13?) having an operational amplifier (40, 42) that uses a voltage divider (115, 116) in a feedback path to control the amount of charge stored on a capacitor (104, 105). During a precharge portion of a read operation, the charge stored on the capacitor (104, 105) is used to precharge the sense amplifier (11). By using charge sharing to precharge the sense amplifier (11), the sense amplifier (11) can be precharged to a steady state common mode voltage more quickly, thus decreasing time required for a read operation.

Abstract: A memory device includes an equalization voltage generator. The equalization voltage generator includes an oscillator and a charge pump to produce a first voltage, which may be used as an equalization voltage for pairs of complementary digit lines. The oscillator is controlled by an oscillator control signal, which is produced by a feedback and control loop of the equalization voltage generator. The feedback and control loop includes a reference generator circuit to produce a stable, internal reference signal that is clamped at a maximum reference voltage. A comparator of the feedback and control loop compares the internal reference signal with a second voltage, which is proportional to the first voltage. The comparator causes the oscillator to turn on when the second voltage is lower than the reference voltage, and causes the oscillator to turn off when the second voltage is higher than the reference voltage.

Abstract: A CAM match detection circuit that maintains established levels of accuracy while greatly reducing the amount of power dissipated is disclosed. Rather than allowing the Matchline 185 voltage to swing between a precharge voltage level of VDD and ground, the Matchline voltage is restricted to swinging between a reduced precharge voltage level (i.e., a voltage level lower than VDD) and ground. Further, a source of a p-type transistor that makes up one transistor in each pair of series connected transistors is coupled to the Matchline thereby further reducing the Matchline swing voltage and the overall power dissipation of the match detection circuit.

Abstract: A sensing circuit including a sense amplifier to resolve a data signal generated by a memory cell is disclosed herein. The sensing circuit includes a bit line to receive the data signal, a first pre-charge device coupled to the bit line and configured to pre-charge the bit line, a device for providing a bias coupled to the bit line and configured to provide a bias to the bit line, and a reference node configured to be at least one pre-determined level. In one embodiment the pre-determined level is equal to a low potential such as ground and in another embodiment equal to a high potential such as VDD. One or more switching devices allows for the activation or deactivation of the pre-charge device allowing to pre-charge the bit line to a certain potential and the sensing circuit quickly and accurately determines whether a logical state of ‘1’ or ‘0’ is being applied to the bit line.

Abstract: There is provided a semiconductor memory device capable of performing high-speed reading even when the current capability of memory cells and transistors for charging is decreased, and a bit line capacitance is increased. In a sense amplifier, in addition to a P-type MOS transistor for charging, a P-type MOS transistor and a N-type MOS transistor are provided as a circuit for charging a selected bit line up to a switching level of a determination inverter included in a circuit for determining data of a memory cell, and a bit line is charged at high speed, whereby a read time is shortened.

Abstract: A sense amplifier is connected to a pair of bit lines to read/write data. A bit line equalizer equalizes the potentials of the pair of bit lines. A sense amplifier equalizer equalizes the potentials of two power supply nodes of the sense amplifier. The sense amplifier equalizer is constituted by two types of MOS transistors whose gate oxide films have different thicknesses. MOS transistors of one type are formed in a thick film type Tr area. MOS transistors of the other type are formed in a thick film type Tr area.