From 86a2af0fa3c5c8c5df0f89686e419f9e2de6e367 Mon Sep 17 00:00:00 2001 From: Greg Chadwick Date: Mon, 4 Nov 2024 11:36:42 +0000 Subject: [PATCH] No default UART TX output to RS485 --- data/top_config.toml | 1 + rtl/system/pinmux.sv | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/data/top_config.toml b/data/top_config.toml index 34131d05e..4e55f89c7 100644 --- a/data/top_config.toml +++ b/data/top_config.toml @@ -553,3 +553,4 @@ block_ios = [{ block = "uart", instance = 2, io = "rx" }] [[pins]] name = "rs485_tx" block_ios = [{ block = "uart", instance = 2, io = "tx" }] +no_default_out = true diff --git a/rtl/system/pinmux.sv b/rtl/system/pinmux.sv index 9dcfd8b2f..cbd9f9330 100644 --- a/rtl/system/pinmux.sv +++ b/rtl/system/pinmux.sv @@ -3961,8 +3961,8 @@ module pinmux always @(posedge clk_i or negedge rst_ni) begin if (!rst_ni) begin - // Select second mux input by default so that pin is connected to the first block that is specified in the configuration. - rs485_tx_sel <= 2'b10; + // Select first mux input (constant) by default so pin is connected to no block initially + rs485_tx_sel <= 2'b1; end else begin if (reg_we & rs485_tx_sel_addressed) begin rs485_tx_sel <= reg_wdata[16+:2];