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Implemented fix from early issue #16. Finally decided to pull the 

trigger on this one in the hopes that it helps prevent user error
in implementing input pull-up and pull-down on GPIO pins.
This commit is contained in:
Tim Edwards 2022-10-05 14:13:57 -04:00
parent 51c6d04e31
commit 577cc12fe0
1 changed files with 19 additions and 6 deletions
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25
verilog/rtl/gpio_control_block.v
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@ -45,7 +45,18 @@
* the clock half cycle. This avoids the need to fine-tune the clock
* skew between GPIO blocks.
*
* Modified 10/05/2022 by Tim Edwards
* Modified 10/4/2022 by Tim Edwards
* Replaces the tri-state output with a zero-value output when the
* user project is powered down (same modification as was made to the
* management protect module). This allows all outputs to be buffered
* and sized by the synthesis tools.
*
* Modified 10/5/2022 by Tim Edwards
* Changed the behavior of the logic for the pad "out" and "oeb"
* pins for the user so that they match the logic used for the
* management SoC, which is to automatically control these values
* when the configuration is set to either input pull-up or input
* pull-down modes.
*
*---------------------------------------------------------------------
*/
@ -235,16 +246,18 @@ module gpio_control_block #(
/* the control block. In this case, the output enable state is */
/* determined by the OEB configuration bit. */
assign pad_gpio_outenb = (mgmt_ena) ? ((mgmt_gpio_oeb == 1'b1) ?
gpio_outenb : 1'b0) : user_gpio_oeb;
assign pad_gpio_outenb =
(gpio_dm[2:1] == 2'b01) ? 1'b0 :
((mgmt_ena) ? ((mgmt_gpio_oeb == 1'b1) ? gpio_outenb : 1'b0) :
user_gpio_oeb);
/* For 2-wire interfaces, if the pad is configured for pull-up or */
/* pull-down, drive the output value locally to achieve the */
/* expected pull. */
assign pad_gpio_out = (mgmt_ena) ? ((mgmt_gpio_oeb == 1'b1) ?
((gpio_dm[2:1] == 2'b01) ? ~gpio_dm[0] : mgmt_gpio_out) :
mgmt_gpio_out) : user_gpio_out;
assign pad_gpio_out =
(gpio_dm[2:1] == 2'b01) ? ~gpio_dm[0] :
((mgmt_ena) ? mgmt_gpio_out : user_gpio_out);
/* Buffer user_gpio_in with an enable that is set by the user domain vccd */