Rainbow Electronics ATF1504ASVL - Manual (Page 4)

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ATF1504ASV(L)
1409H–PLD–09/02
Description
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-
ces 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
control 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-
tions. The ATF1504ASV(L) contains four such logic chains, each capable of creating
sum 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-
complex 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.