max10, fiftyfivenm_crcblock, crc error do re config internally?

[Altera_Forum]

Hi 

Im using max10 and need to detect seu error for crc.  Is it necessary to use the block fiftyfivenm_crcblock  if I want to access the crc_error from the error detection logic by internal logic? If so how to get the crc_error routed to the crc_error pin and also access it for other logic as fiftyfivenm_crcblock? A AN note says it could be routed to a bidir pin and then routed to the fiftyfivenm_crcblock, but how? The max10 have a crc_error pin which  is a pure output, not a bidir pin ~ALTERA_CRC_ERROR~ : D6 : output.  Also how could I by only using internal logic detect an crc-error and then force a re-configuration (force eg nconfig) without using any external logic at all? Is it necessary to use the fiftyfivenm_rublock and if so how to use it as a simple internal re-config controller?  fiftyfivenm_crcblock port map (  clk => pld_clk,  shiftnld => shiftnld,  ldsrc => ldsrc,  crcerror => mapp to what and how,  regout => regout

[Altera_Forum]

I am also interessed on this issue.

[TWend1]

Although the original question is about 2 years old, I think this solution can be of interrest to others as well.

Most of this is based on the Max10 Handbook page 3-9 "Accessing Error Detection Block Through User Interface" and some guessing and trying of the actual vhdl component interface.

Through try and error, I determined it also needed an lcell (or non-trivial logic) in order to route the crc output signal to arbitrary pins. Without it, it was limited to the special-use crc_error pin.

The uses of the internal output signal of the crcblock does not require one to activate the external crc_error pin in the device settings.

I only tried this in Quartus 18.1, not in hardware yet:

library ieee; use ieee.numeric_std.all; use ieee.std_logic_1164.all; library lpm; use lpm.all;   entity XYZ is port( ErrorOut : out std_logic ); end entity;   architecture arch of XYZ is   component fiftyfivenm_crcblock is generic ( oscillator_divider : integer range 2 to 256 := 1 -- default is nonsense ); port ( clk : in std_logic := '0'; shiftnld : in std_logic := '0'; ldsrc : in std_logic :='0'; crcerror : out std_logic; regout : out std_logic ); end component;   component lcell is port ( a_in : in std_logic; a_out : out std_logic); end component;   signal CRC : std_logic; signal CRC_lcell : std_logic;   begin X1: fiftyfivenm_crcblock generic map( oscillator_divider => 256 ) port map( crcerror => CRC ); L1: lcell port map( a_in => CRC, a_out => CRC_lcell ); ErrorOut <= '0' when CRC_lcell='1' else 'Z'; -- Open drain output with proper polarity for nConfig end architecture;

(The code is taken from a larger code block for one of my projects.)

Some other remarks about the crc error block:

- It looks like the crcblock was part of the old megawizard plugin, but it has no equivalent in the new IP catalog.

- Based on the documentation I conclude that a crc error does not automatically induce a reload of the configuration. I also noted that the polarity of the crc_error pin and the nConfig pin is opposite - direct connection will not work.