Multi-Gbps serial link transmitter for both off-chip and on-chip transmission are presented. For off-chip transmission, a new pre-emphasis design methodology and circuits for a 4/2 PAM transmitter over cable are proposed. A test chip of transmitter with pre-emphasis, PLL circuit and on-chip termination resistors is implemented using tsmc 0.18 um CMOS process. The measurement results of 10/5 Gbps (4/2 PAM) are carried out over 5 meter (m) long cable and is in agreement with our analysis and simulation results. For on-chip transmission, SerDes based serial link architecture is used in on-chip application. Using tsmc 0.13 um CMOS process, the operation speed and power consumption are 5 Gbps and 3.2 mW respectively with the interconnect area is half of parallel architecture.