US Patent 7869153 Self servo write tune feature for preamps

A system includes N channels and a control module. Each of the N channels includes a latch and a signal generator module, where N is an integer greater than 1. The latch selectively latches a B-bit codeword, where B is an integer greater than 1. The signal generator module generates a signal based on the B bit codeword. The control module transmits the B-bit codeword via a B-bit data bus to the latch of each of the N channels. The control module generates control signals that select the latch in at least one of the N channels.