name: HT99U210C function: Enhanced Cordless Phone Controller package: SKDIP/SOP24,24 manufacturer: Holtek +--()--+ PA7(C8B) | 1 24| PA6(C7B) PB0(R1B) | 2 23| PA5(C6B) PB1(R2B) | 3 22| PA4(C5B) PB2(R3B) | 4 21| PA3(C4B) PB3(R4B) | 5 20| PA2(C3B) PB4(R5B) | 6 19| PA1(C2B) PD2(HKSB) | 7 18| PA0(C1B) PD6(MODE) | 8 17| PC4(POB) X1 | 9 16| PC2(XMUTEB) X2 |10 15| DTMF VDD |11 14| PC1(HDIB) VSS |12 13| PC0(HDO) +------+ This pinout came from the Chipdir: http://www.chipdir.org/