Write a subroutine at address 0x150 in pic18f assembly

Question

Question: Write a subroutine at address 0x150 in PIC18F assembly language to convert a 3-digit unpacked BCD number to binary using unsigned multiplication by 10, and additions. The most significant digit is stored in a memory location starting at register 0x30, the next digit is stored at 0x31, and so on. Store the 8-bit binary result (N) in register 0x50. Note that arithmetic operations for obtaining N will provide binary result. Use the value of the 3-digit BCD number,

N = N2 x 10² + N1 x 10¹ + N0
    = ((10xN2)+N1)x10+N0