As time-to-market pressure increases, design engineers require advanced system-level products to ensure problem-free development and manufacturing. Programmable logic devices (PLDs) with in-system programmability (ISP) can help accelerate development time, facilitate in-field upgrades, simplify the manufacturing flow, lower inventory costs, and improve printed circuit board (PCB) testing capabilities. Altera?ISP-capable MAX?II devices can be programmed and reprogrammed in-system via the IEEE Std. 1149.1 Joint Test Action Group (JTAG) interface. This interface allows MAX II devices to be programmed and the PCB to be functionally tested in a single manufacturing step, saving testing time and assembly costs. This chapter describes guidelines you should follow to design successfully with ISP, including:    General ISP Guidelines     IEEE Std. 1149.1 Signals    Sequential vs. Concurrent Programming    ISP Troubleshooting Guidelines    ISP via Embedded Processors     ISP via In-Circuit Testers……