ATF1504ASV

The ATF1504ASV(L) is a high-performance, high-density complex programmable logic device (CPLD) that utilizes Atmel's proven electrically-erasable memory technology.With 64 logic macrocells and up to 68 inputs, it easily integrates logic from several TTL,SSI, MSI, LSI and classic PLDs.

The ATF1504ASV(L)'s enhanced routing switch matri-es increase usable gate count and the odds of successful pin-locked design modifications.The ATF1504ASV(L) has up to 68 bi-directional I/O pins and four dedicated input pins,depending on the type of device package selected. Each dedicated pin can also serve as a global control signal, register clock, register reset or output enable. Each of these ontrol signals can be selected for use individually within each macrocell. Each of the 64 macrocells generates a buried feedback that goes to the global bus.Each input and I/O pin also feeds into the global bus. The switch matrix in each logic block then selects 40 individual signals from the global bus. Each macrocell also gener-ates a foldback logic term that goes to a regional bus. Cascade logic between macrocells in the ATF1504ASV(L) allows fast, efficient generation of complex logic func-ions.

The ATF1504ASV(L) contains four such logic chains, each capable of creating um term logic with a fan-in of up to 40 product terms.The ATF1504ASV(L) macrocell, shown in Figure 1, is flexible enough to support highly-omplex logic functions operating at high speed. The macrocell consists of five sections:product terms and product term select multiplexer, OR/XOR/CASCADE logic, a flip-flop,output select and enable, and logic array inputs.