name: HT9315DR function: 15-Memory with ABR Tone/Pulse Dialer package: SKDIP28,28 manufacturer: Holtek +--()--+ LEDB | 1 28| ALARM RINGB | 2 27| AIN C1B | 3 26| R4B C2B | 4 25| R3B C3B | 5 24| R2B C4B | 6 23| R1B C5B | 7 22| MODE X1 | 8 21| DTMF X2 | 9 20| POB XMUTEB |10 19| HKSB VSS |11 18| VDD HFI |12 17| HFO DOUT |13 16| CLOCK LOCKB |14 15| HKOPT +------+ This pinout came from the Chipdir: http://www.chipdir.org/