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How to increase data of std_logic_vector by 1 in VHDL-2002

Started by W TX May 24, 2021
Hi,
It is a long time headache for me to increase a data of std_logic_vector by 1.

Here are examples:
LIBRARY ieee;
USE ieee.std_logic_1164.all;
use ieee.numeric_std.all;

constant ONE : std_logic_vector(7 downto 0);
signal   Series_Number : std_logic_vector(7 downto 0);
...
All followings generate errors in VHDL-2002:
Series_Number <= Series_Number +1;
Series_Number <= Series_Number +'1';
Series_Number <= Series_Number+std_logic_vector(unsigned(Series_Number)+1);
Series_Number <= Series_Number+ONE;

Thank you. 

Weng
> Series_Number <= Series_Number+std_logic_vector(unsigned(Series_Number)+1); > Series_Number <= std_logic_vector (unsigned (Series_Number) + 1);
Series_Number <= std_logic_vector (unsigned (Series_Number) + 1); 
On Sunday, May 23, 2021 at 10:22:23 PM UTC-7, andrew_b wrote:
> Series_Number <= std_logic_vector (unsigned (Series_Number) + 1);
andrew_b, thank you!!! Weng
On Monday, May 24, 2021 at 3:00:28 AM UTC-7, Tianxiang Weng wrote:
> On Sunday, May 23, 2021 at 10:22:23 PM UTC-7, andrew_b wrote: > > Series_Number <= std_logic_vector (unsigned (Series_Number) + 1); > andrew_b, thank you!!! > > Weng
Hi, I now ha another similar problem: how to change an integer to a std_logic_vector. Here is a code snippet: signal X :integer range 0 to 15; signal Y :
On Tuesday, June 22, 2021 at 3:18:18 AM UTC-7, Tianxiang Weng wrote:
> On Monday, May 24, 2021 at 3:00:28 AM UTC-7, Tianxiang Weng wrote: > > On Sunday, May 23, 2021 at 10:22:23 PM UTC-7, andrew_b wrote: > > > Series_Number <= std_logic_vector (unsigned (Series_Number) + 1); > > andrew_b, thank you!!! > > > > Weng
Hi, I now have another similar problem: how to change an integer to a std_logic_vector.in VHDL-2002. Here is a code snippet: signal X :integer range 0 to 15; -- X is used as an index to an array. signal Y :std_logic_vector(3 downto 0); -- Y is a device input interface so Y data type cannot change, but X may be. Y <= std_logic_vector(X); -- error! Thank you. Weng
On Tuesday, June 22, 2021 at 3:27:40 AM UTC-7, Tianxiang Weng wrote:
> On Tuesday, June 22, 2021 at 3:18:18 AM UTC-7, Tianxiang Weng wrote: > > On Monday, May 24, 2021 at 3:00:28 AM UTC-7, Tianxiang Weng wrote: > > > On Sunday, May 23, 2021 at 10:22:23 PM UTC-7, andrew_b wrote: > > > > Series_Number <= std_logic_vector (unsigned (Series_Number) + 1); > > > andrew_b, thank you!!! > > > > > > Weng > Hi, > I now have another similar problem: how to change an integer to a std_logic_vector.in VHDL-2002. > Here is a code snippet: > signal X :integer range 0 to 15; -- X is used as an index to an array. > signal Y :std_logic_vector(3 downto 0); -- Y is a device input interface so Y data type cannot change, but X may be. > > Y <= std_logic_vector(X); -- error! > > Thank you. > > Weng
Hi, In https://groups.google.com/g/comp.arch.fpga/c/vkeCNxzCvdc/m/wOk5AZVR0ksJ, I learned the solution: Y <= std_logic_vector(to_unsigned(X, WIDTH)); Thank you. Weng
Tianxiang Weng <wtxwtx@gmail.com> writes:

> I now ha another similar problem: how to change an integer to a std_logic_vector. > > Here is a code snippet: > signal X :integer range 0 to 15; > signal Y :
Maybe save a copy of this: https://www.synthworks.com/papers/vhdl_math_tricks_mapld_2003.pdf It has pretty good coverage on type conversions in VHDL.
On Wednesday, June 23, 2021 at 1:42:41 AM UTC-7, Anssi Saari wrote:
> Tianxiang Weng <wtx...@gmail.com> writes: > > > I now ha another similar problem: how to change an integer to a std_logic_vector. > > > > Here is a code snippet: > > signal X :integer range 0 to 15; > > signal Y : > Maybe save a copy of this: > > https://www.synthworks.com/papers/vhdl_math_tricks_mapld_2003.pdf > > It has pretty good coverage on type conversions in VHDL.
Hi, Thank you. When I opened the *.pdf file and planned to save it, a surprising thing happened: my computer has already had a copy of it. After downloading it, I never read it. Its name is "DRAFT Standard for Floating-Point Arithmetic P754-Draft 129", I thought it is for Floating-Point Arithmetic only, and I never use Floating-Point Arithmetic in VHDL. After your post, I changed the pdf file name to "VHDL-Type conversion". This time I will read it carefully. Weng