此电路的电路分析,求大神指导

R1 = 4K7
R2, R8 = 1M
R3, R4, R9, R10, R11, R12, R13 = 100K
R5 = 1K
R6, R7 = 470K
R14, R15 = 220
C1 = 22 p
C2 = 82 p
C3, C4, C5, C6 = 220n
IC1 = 4521
IC2 = 4017
D1, D2, D4 = 1N4148
cristal = 4.1943 Mhz
D3 = LED 3 mm
2 x IC sockets 16 pin

求大神指导