Concurrent Rules¶
concurrent_001¶
This rule checks the indent of concurrent assignments.
Violation
architecture RTL of FIFO is
begin
wr_en <= '0';
rd_en <= '1';
Fix
architecture RTL of FIFO is
begin
wr_en <= '0';
rd_en <= '1';
concurrent_002¶
This rule checks for a single space after the <= operator.
Violation
wr_en <= '0';
rd_en <= '1';
Fix
wr_en <= '0';
rd_en <= '1';
concurrent_003¶
This rule checks alignment of multiline concurrent assignments. Succesive lines should align to the space after the assignment operator. However, there is a special case if there are parenthesis in the assignment. If the parenthesis are not closed on the same line, then the next line will be aligned to the parenthesis. Aligning to the parenthesis improves readability.
Violation
wr_en <= '0' when q_wr_en = '1' else
'1';
w_foo <= I_FOO when ((I_BAR = '1') and
(I_CRUFT = '1')) else
'0';
O_FOO <= (1 => q_foo(63 downto 32),
0 => q_foo(31 downto 0));
n_foo <= resize(unsigned(I_FOO) +
unsigned(I_BAR), q_foo'length);
Fix
wr_en <= '0' when q_wr_en = '1' else
'1';
w_foo <= I_FOO when ((I_BAR = '1') and
(I_CRUFT = '1')) else
'0';
O_FOO <= (1 => q_foo(63 downto 32),
0 => q_foo(31 downto 0));
n_foo <= resize(unsigned(I_FOO) +
unsigned(I_BAR), q_foo'length);
concurrent_004¶
This rule checks for at least a single space before the <= operator.
Violation
wr_en<= '0';
Fix
wr_en <= '0';
concurrent_005¶
This rule checks for labels on concurrent assignments. Labels on concurrents are optional and do not provide additional information.
Violation
WR_EN_OUTPUT : WR_EN <= q_wr_en;
RD_EN_OUTPUT : RD_EN <= q_rd_en;
Fix
WR_EN <= q_wr_en;
RD_EN <= q_rd_en;
concurrent_006¶
This rule checks the alignment of the <= operator over multiple consecutive lines. Refer to the section Configuring Keyword Alignment Rules for information on changing the configurations.
Violation
wr_en <= '0';
rd_en <= '1';
data <= (others => '0');
Fix
wr_en <= '0';
rd_en <= '1';
data <= (others => '0');
concurrent_007¶
This rule checks for code after the else keyword.
Note
There is a configuration option allow_single_line which allows single line concurrent statements.
allow_single_line set to False (Default)¶
Violation
wr_en <= '0' when overflow = '0' else '1';
wr_en <= '0' when overflow = '0' else '1' when underflow = '1' else sig_a;
Fix
wr_en <= '0' when overflow = '0' else
'1';
wr_en <= '0' when overflow = '0' else
'1' when underflow = '1' else
sig_a;
allow_single_line set to True¶
Violation
wr_en <= '0' when overflow = '0' else '1';
wr_en <= '0' when overflow = '0' else '1' when underflow = '1' else sig_a;
Fix
wr_en <= '0' when overflow = '0' else '1';
wr_en <= '0' when overflow = '0' else
'1' when underflow = '1' else
sig_a;
concurrent_008¶
This rule checks the alignment of inline comments in sequential concurrent statements. Refer to the section Configuring Keyword Alignment Rules for information on changing the configurations.
Violation
wr_en <= '0'; -- Write enable
rd_en <= '1'; -- Read enable
data <= (others => '0'); -- Write data
Fix
wr_en <= '0'; -- Write enable
rd_en <= '1'; -- Read enable
data <= (others => '0'); -- Write data