A touch circuit comprising: a first circuit (ROIC) configured to receive a downlink signal (DLS #1,..., DLS #N) output from each of two or more pens (Pen #1,..., Pen #N) through a panel on which a plurality of touch electrodes is arranged; and a second circuit configured to sense the two or more pens (Pen #1,..., Pen #N) such that the two or more pens (Pen #1,..., Pen #N) are distinguished based on unique information (UI #1,..., UI #N) of the received downlink signal (DLS #1,..., DLS #N), wherein the touch circuit is configured to supply an uplink signal including available unique information to the panel and receive a downlink signal (DLS #1,..., DLS #N) having unique information (UI #1,..., UI #N) determined according to the available unique information from a respective pen (Pen #1,..., Pen #N) in contact with or in proximity to the panel through the panel; and wherein the touch circuit is configured such that, when the touch circuit receives downlink signals (DLS #1, DLS #2) having same unique information (UI #1, UI #1) from first and second pens (Pen #1, Pen #2) of the two or more pens (Pen #1,..., Pen N) through the panel after supplying the uplink signal including the available unique information to the panel, - to recognize position of the first and second pens (Pen #1, Pen #2), - to output an uplink signal containing a reset signal only to the second pen (Pen #2) for causing the second pen (Pen #2) to release a previously set unique information (UI #2) and to output an uplink signal containing new available unique information (AUI') to the second pen (PEN #2) by outputting the uplink signal containing the reset signal and the uplink signal containing new available unique information (AUI') only to a particular area in which the touch electrode of the plurality of touch electrodes corresponding to the position of the second pen (PEN #2) on the touch panel is disposed, while not to output the uplink signal containing the reset signal to the first pen (Pen #1) having sent the downlink signal (DLS #1) having the same unique information (UI #1, UI #1) as the second pen (Pen #2), and thereafter - to receive a downlink signal (DLS #2) having a second unique information (UI #2) by using the received new available unique information (AUI')from the second pen (Pen #2). a first circuit (ROIC) configured to receive a downlink signal (DLS #1,..., DLS #N) output from each of two or more pens (Pen #1,..., Pen #N) through a panel on which a plurality of touch electrodes is arranged; and a second circuit configured to sense the two or more pens (Pen #1,..., Pen #N) such that the two or more pens (Pen #1,..., Pen #N) are distinguished based on unique information (UI #1,..., UI #N) of the received downlink signal (DLS #1,..., DLS #N), wherein the touch circuit is configured to supply an uplink signal including available unique information to the panel and receive a downlink signal (DLS #1,..., DLS #N) having unique information (UI #1,..., UI #N) determined according to the available unique information from a respective pen (Pen #1,..., Pen #N) in contact with or in proximity to the panel through the panel; and wherein the touch circuit is configured such that, when the touch circuit receives downlink signals (DLS #1, DLS #2) having same unique information (UI #1, UI #1) from first and second pens (Pen #1, Pen #2) of the two or more pens (Pen #1,..., Pen N) through the panel after supplying the uplink signal including the available unique information to the panel, - to recognize position of the first and second pens (Pen #1, Pen #2), - to output an uplink signal containing a reset signal only to the second pen (Pen #2) for causing the second pen (Pen #2) to release a previously set unique information (UI #2) and to output an uplink signal containing new available unique information (AUI') to the second pen (PEN #2) by outputting the uplink signal containing the reset signal and the uplink signal containing new available unique information (AUI') only to a particular area in which the touch electrode of the plurality of touch electrodes corresponding to the position of the second pen (PEN #2) on the touch panel is disposed, while not to output the uplink signal containing the reset signal to the first pen (Pen #1) having sent the downlink signal (DLS #1) having the same unique information (UI #1, UI #1) as the second pen (Pen #2), and thereafter - to receive a downlink signal (DLS #2) having a second unique information (UI #2) by using the received new available unique information (AUI')from the second pen (Pen #2). - to recognize position of the first and second pens (Pen #1, Pen #2), - to output an uplink signal containing a reset signal only to the second pen (Pen #2) for causing the second pen (Pen #2) to release a previously set unique information (UI #2) and to output an uplink signal containing new available unique information (AUI') to the second pen (PEN #2) by outputting the uplink signal containing the reset signal and the uplink signal containing new available unique information (AUI') only to a particular area in which the touch electrode of the plurality of touch electrodes corresponding to the position of the second pen (PEN #2) on the touch panel is disposed, while not to output the uplink signal containing the reset signal to the first pen (Pen #1) having sent the downlink signal (DLS #1) having the same unique information (UI #1, UI #1) as the second pen (Pen #2), and thereafter - to receive a downlink signal (DLS #2) having a second unique information (UI #2) by using the received new available unique information (AUI')from the second pen (Pen #2).