name: HT9315CV function: 15-Memory Tone/Pulse Dialers with Volume Switches package: SKDIP22,22 manufacturer: Holtek +--()--+ S1 | 1 22| S2 C1B | 2 21| R4B C2B | 3 20| R3B C3B | 4 19| R2B C4B | 5 18| R1B C5B | 6 17| MODE/KT X1 | 7 16| DTMF X2 | 8 15| POB XMUTEB | 9 14| HKSB VSS |10 13| VDD DOUT |11 12| CLOCK +------+ This pinout came from the Chipdir: http://www.chipdir.org/