Questions tagged [programmable-logic]
Programmable digital logic devices include FPGAs, CPLDs, and older devices such as GALs and PALs. Programmable logic enables flexibly implementing complex digital functions in a single chip, from a few gates of glue logic to entire microprocessors or complex signal processing systems.
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Why do PALs have higher speed than PLAs?
When considering speed I have learned that PLAs are much slower than PALs. As each signal has to propagate through same sequence of gates (in series) why there is a speed difference?
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How to fix erased On-Board Usb-Blaster FPGA (MAX II EPM240T100C3 on board Terasic DE10-Lite)
I have Terasic DE10-Lite board (with Altera MAX10 fpga), which use Altera Max II EPM240T100C3N (and usb-b + ftdi chip) for on-board usb-blaster logic. After explore 8 pins jtag holes on the board, i ...
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How to flash Altera EPM7256E?
I am working on legacy bit of hardware. I see that EPM7256S can be flashed as usual, via JTAG using standard (modern) tools, so this is quite clear.
But how to flash EPM7256E? Are the any inexpensive ...
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Defining arbitrary length bit-string literals for constant std_ulogic_vector in VHDL
I want to be able to define a simple constant for DEFAULT_BUS as all Z, or some other std_ulogic value, but its length should depend upon another generic value as per instantiation and it'd be nice to ...
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Having a Counter issue on a PLD, programmed from NI MultiSim
In a PLD build:
I have built a counter that counts 0-9 combined to a second counter that counts to 8, to create a counter that counts up to 80. It has a reset and hold (@80) function as well. I have ...
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What is the algorithm to read fusemap from PAL IC?
I am aware that it's not always possible due to security fuse, but I would like to at least try to read the fusemap from a certain PAL16R6 chip. I would like to do it using MCU like Arduino, not a ...
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How to combine two, separate 4 bit words into a 6 bit one?
How to combine two, 4-bit words into one 6-bit word.
What I want to achieve: Using a matrix keyboard, I would like to control six addresses (A0-A5) of a parallel EEPROM memory in the range from 000000 ...
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Composite video with 8-bit DAC
recently my eyes got caught by this YouTube video
It shows how ESP32 can draw analog composite video using I2S -> DMA -> DAC.
I considered using this concept in my project but it has a little ...
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How to estimate GreenPAK speed limits?
I am considering using a SLG46826 GreenPAK PLD for a simple digital design running at 40 MHz. Basically output a 40 MHz external clock and generate a properly synchronized pulse now and then. In the ...
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What logic function performs this IEEE Standard 91-1984 symbol?
I'm thinking about copying network interface card for an old HP9000/300 series computer. These cards are insanely expensive on ebay these days (around 200USD), and i think that i could make one for ...
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How can I improve my ladder logic diagram of a vending machine?
I am trying to create a coffee and tea machine using a ladder logic diagram. There are small, medium, and large sizes. This is where I am now:
Can you give me any ideas or corrections on how to ...
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Lowering VCE(sat) for analog transistor switch
I've been wanting to build a primitive programmable logic device using mainly bipolar transistors.
One of the defining characteristics of a PLD is the ability to select what inputs get passed through ...
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Atmel Micro-controller on a Xilinx CPLD board
This question is related to the CoolRunner-II Starter Board that was used to be offered from Digilent. See here for schematic. See here for the reference manual. Here is the block diagram for the CPLD ...
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What is this chip? Is it re-programmable? [duplicate]
I found this chip inside my kid's walker. Seems like it stores the pre-installed audios of children's rhymes. It's connected to several LEDs, a mono speaker and two button pcbs. I wanna replace the ...
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Understanding OLD PEEL173 code
I have some code for a PEEL173 form the early 90's. I would like to understand the logic of this code, but I don't recognize this syntax.
Question 1: Do you recognize the syntax of this language? What ...
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