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Complex Programmable Logic Devices. EE 365. PLDs. 16V8 (20 Pins) can have 16 inputs (max) and/or 8 outputs (marcrocells) has 32 inputs to each of the AND gates (product terms) 22V10 (24 pins) can have 22 inputs and/or 10 outputs (max) has 44 inputs to each of the AND gates
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PLDs • 16V8 (20 Pins) • can have 16 inputs (max) and/or 8 outputs (marcrocells) • has 32 inputs to each of the AND gates (product terms) • 22V10 (24 pins) • can have 22 inputs and/or 10 outputs (max) • has 44 inputs to each of the AND gates • How about a “128V64” for larger applications? • It will be slower and will more wasted silicon space • Solution? Use CPLDs
The OR gates XOR gates to make inverting or non-inverting buffer GAL16V8(review seq_1.ppt) • Each output is programmable as combinational or registered • Also has programmable output polarity And Plane
A General CPLD structure A collection of PLDs on a single chip with Programmble interconnects
Let’s takes a look at this Who makes the CPLDs? Manufacturer CPLD Products URL AlteraMAX 5000, 7000 & 9000 www.altera.com Altmel ATF & ATV www.atmel.com Cypress FLASH370, Ultra37000 www.cypress.com Lattice ispLSI 1000 to 8000 www.latticesemi.com Philips XPLA www.philips.com Vantis MACH 1 to 5 www.vantis.com Xilinx XC9500 www.xilinx.com
The Xilinx 9500-series CPLD • The internal PLDs are called Configurable Functional Blocks • (FBs or CFBs) • Each FB has 36 inputs and 18 Macrocells (effectively a “36V18”) • Each CLPD is packaged in a plastic-leaded chip carrier (PLCC) • The number of I/O pins are much less than the total number of • Macrocells in family of devices
Architecture of Xilinx 9500-family CPLD 36 Signal pins 18 outputs Global Clock Global set/reset 18 Output enable signals Global 3 state control
Architecture of Xilinx FB Most CLPDs have fewer AND terms per macrocell XC9500 has 5 whereas 16V8 has 8 and 22V10 has 8-16 But…each macrocell can use unused ANDs froms its neigboring macrocells using the “product-term-allocators”
XC9500 Product term allocator and macrocell