TC9157AP Digital Tuning System IC 
From a big 32- page datasheet in the TOSHIBA databook 
Audio Digital ICs 1989. 

Pins: 
1 : Gnd 
2 : XT = Crystal Osc 7.2 MHz, built in feedback resistor 
3 : /XT = ... 
4 : FM band select 
5 : MW ... 
6 : LW ... 
7 : Manual Tuning designating Input 
8 : Auto Search Tuning... 
9 : Up 
10 : Down 
11 : Memory Store Command 
12 : Memory 1 
... 
19 : Memory 8 
20 : Memory Control Input: Vdd for Channels 1 to 8 
21 : ...., for Channels 9 to 16 
22 : OSC2, Scan Oszillator for AM search, R and C to Gnd 
23 : OSC1, ... for FM search. 
24 : 50 kHz step output (in FM) 
25 : CK2 (output)\ for the Display Driver TD6301 
26 : CK1 ... / 
27 : Data ... / 
28 : MUTE 
29 : E2 Region Input 
30 : E1 ... 
31 : AM-IF input stops search 
32 : Auto search stop input 
33 : Scan speed slow input 
34 : DO2 PLL Phase Coparator output, tri-state 
35 : DO1 ... 
36 : Test input 
37 : PLL FM input frequency from prescaler 
38 : Output for prescaler 1/30 to 1/31 division 
39 : PLL AM input (local osc.) 
40 : /INH inhibit input 
41 : /INT initialize input 
42 : Vdd = 5 V 

Pins 4 to 8 and 11 to 19 are Input/Outputs having internal 
sink FET for external LED to Vdd, and internal NPN Emitter 
Follower source for external loads to Gnd. 

Pins 9, 10 and 36 have internal pull down resistor, the other 
inputs are standard CMOS.