Hi all,
I have an OPB_GPIO module configured as all outputs. It is a part of an EDK system which is instantiated as a module in a top-level ISE project. I am using d_outs from the GPIO module. When I tried inserting some logic between these outputs and the top level pins I got the following error:
ERROR:NgdBuild:809 - output pad net 'gpio_leds' has an illegal load: pin I2 on block _n00141 with type LUT3
So, does that mean that I can't drive any internal logic with GPIO outputs?
Thanks, /Mikhail
GPIO outputs can drive internal logic. Sometimes it's easier than building an IPIF interface. I'm going to take a guess and say that you connected your internal logic input to the IOB instead of to the GPIO.
Post the code if you want someone to figure it out.
Here it goes (with most of the unrelated stuff deleted):
entity top is Port ( Led : out std_logic_vector(12 downto 1); );
end top;
architecture top_rtl of top is
component system_stub is port ( -- skip -- fpga_0_GPIO_LED_d_out_pin : out std_logic_vector(0 to 19); -- skip -- ); end component;
signal gpio_leds : std_logic_vector(0 to 19); signal led_tick : std_logic;
begin
PPC_INST: system_stub port map ( -- skip -- fpga_0_GPIO_LED_d_out_pin => gpio_leds, -- skip -- );
LED_GEN: for i in 0 to 7 generate Led(i+1)
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