AMORTIZATION OF ZERO COUPON BINDS

Hi

Since they are issued at discount and redeemed at par, when we establish the EIR to amortise it, can we discount it with bond and show the the difference as discount? 

Eg 1000 face value bond at 10% market rate discounted the bond to 621 for 5 years, can I treat this as the discount and debit the difference between 1000- 621 to p and l? Then start amortising the bond from 621? 

I meant bonds in the heading, and editing did not help.

Txs