USA Paying for Software after Depreciation

[Ve An]

I am planning to sell the software to the C-Corp. The software is custom made, not off-the-shelf one, so it will be entirely depreciated within 3 years. Under the IP assignment agreement, the C-Corp must pay for the software in 1 payment within 5 years - after full depreciation. The C-Corp uses cash accounting method. So, do I get it right that the C-Corp: (1) may depreciate the software before it pays for it; and (2) will not pay any tax, which will relate to this transaction?