May I ask which cpld chip has the least resources, and I want to use a very small one? Thank you!!!

There are a lot of cheap cplds, but you also have to choose the closed device according to your system requirements, otherwise it may cause insufficient resources to dig the shirt, if the clock frequency is not high, you can also use a single-chip microcomputer, this is much cheaper.

The EPM7128 pin has a maximum output current of 25mA, and the on-voltage VF of a common light-emitting diode is about 2V.

i=(5v-vf)/1k= 3ma

The current of the 2 LEDs is about 6mA and there is no problem with this circuit.

...chip, which is also the main reason why the burning system** is much higher than the U disk. There are 8 main manufacturers of Nor-type flash chips in the world, Intel and.

Of course, due to the process and cost of CPLD itself, the price of this kind of flashed cassette is relatively high, and the power consumption is slightly larger, but these shortcomings do not hinder.

You need a physical exercise, two methods:

1) Do it all by yourself and have enough food and clothing. Draw the PCB, then produce, buy a lot of components, solder ......

2) Buy CPLD's development board, based on the development board exercises, time, and economic costs are relatively low, look for them on taobao, a lot, very cheap.

Then it's hard to laugh and quarrel, first extract the hard core (the hardware circuit used), then optimize the circuit, and then draw the chip layout, hand it over to the mask manufacturer, Mr. produces the mask, and then hand it over to the chip manufacturer according to your requirements for the process to produce the chip. The whole process will cost more than 1 million (the most Liang Liang carries the low).

Why not use an FPGA board, the cost performance and scope of application are better than CPLD's.

Over the decades, many companies have developed CPLD programmable logic devices. The more typical products are the products of the three authoritative companies in the world, Altera, Lattice, and Xilinx, and the commonly used chips are given here:

altera epm7128s (plcc84)lattice lc4128v (tqfp100)xilinx xc95108 (plcc84) xc95144

Generally, CPLDs are nonvolatile.

Commonly used is Altera's EPM7128

XC9500 series from Xilinx.