uart

UART communication in Gem5 with ARM Bare-metal

由 依然范特西╮ 提交于 2019-12-20 02:35:36
问题 I am currently working with Gem5 and I have to access via UART from my Host to ARMv8 bare-metal option, so i tried lots way but i stocked yet. could you please let me know, how can i map my host's Serial port to ARMv8's Serial Port in bare-metal type programming. Any help would be appreciated 回答1: Working setups This repository contains a highly automated working example. Features: works on both QEMU and gem5 works on both arm and aarch64 newlib allows using the standard C library optionally

Why characters received in serial connection only after pressing enter?

由 佐手、 提交于 2019-12-17 20:52:27
问题 I have a simple PC to board connection using serial (9600, no parity, 8 bits, no hw flow) I opened simple terminal *with teraterm) in PC and enter keys in teraterm and in board, I just do cat /dev/ttyO5 I see the pressed characters in scope, but I see the characters in the board console, only after pressing "enter" in teraterm (as if they are stored in some FIFO in Linux driver which only enter triggers out) why are the characters received in Linux driver only when pressing enter key ? Is

总线

由 若如初见. 提交于 2019-12-15 20:58:04
总线有三种：内部总线、系统总线和外部总线。内部总线是微机内部各外围芯片与处理器之间的总线，用于芯片一级的互连；而系统总线是微机中各插件板与系统板之间的总线，用于插件板一级的互连；外部总线则是微机和外部设备之间的总线，微机作为一种设备，通过该总线和其他设备进行信息与数据交换，它用于设备一级的互连。 除了总线外，还有一些接口，他们是多种总线的集合体，或者说来者不拒。 SPI SPI（Serial Peripheral Interface): MOTOROLA公司提出的同步串行总线方式。高速同步串行口。3~4线接口，收发独立、可同步进行。 因硬件功能强大而被广泛应用。在单片机组成的智能仪器和测控系统。如果对速度要求不高，采用SPI总线模式十个不错的选择。他可以节省I/O端口，提高外设的数目和系统性能。标准SPI总线由四根线组成：串行时钟线（SCK）、主机输入/从机输出线（MISO）、主机输出/从机输入线（MOSI）和片选信号（CS）。有的SPI接口芯片带有中断信号线或没有MOSI。 SPI总线由三条信号线组成：串行时钟（SCLK）、串行数据输出（SDO)、串行数据输入（SDI）。SPI总线可以实现多个SPI设备互相连接。提供SPI串行时钟的SPI设备为SPI主机或者主设备间可以实现全双工通信，当有多个从设备时，还可以增加一条从设备选择线。如果用通用IO口模拟SPI总线，必须要有一个输出口

FPGA串口通信

由 久未见 提交于 2019-12-15 16:20:45
`timescale 1ns / 1ps ////////////////////////////////////////////////////////////////////////////////// // Engineer: ian // // Create Date: 2019/11/30 14:51:50 // Design Name: uart // Module Name: uart_tx // Project Name: // Target Devices: zynq 7020 // Tool Versions: vivado 2018.3 // Description: This this a uart transmit module // // Dependencies: // // Revision: v1.0 ////////////////////////////////////////////////////////////////////////////////// //********************************************************************************** //input port: sys_clk //system clock // sys_rst_n /

Send a structure using UART [closed]

由 ＊爱你＆永不变心＊ 提交于 2019-12-14 04:14:49
问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed last year . I have a two boards: - Master board (M board) - Slave board (S board) M board shall send a request to S board and the latter shall answer. The answer of the slave is a struct: typedef struct{ uint8_t userID; uint8_t userPass; uint16_t userData; }UserTypeDef; UserTypeDef User;

Uart dma receive interrupt stops receiving data after several minutes

由 删除回忆录丶 提交于 2019-12-14 03:16:10
问题 I have a project that I have used stm32f746g discovery board. It receives data with fixed size from Uart sequentially and to inform application about each data receive completed, dma callback is used (HAL_UART_RxCpltCallback function). It works fine at the beginning but after several minutes of running, the dma callback stops to be called, and as a result, the specified parameter value doesn't get updated. Because the parameter is used in another thread too (actually a rtos defined timer), I

Display previously received UART values

由 夙愿已清 提交于 2019-12-13 17:22:31
问题 This should be easy to answer to anyone familiar with C. I want to display the previous values of a variable (receive register of a UART (RS-232) on a microcontroller) on an LCD. This is my current implementation and it works ok. But I'd like to know if there is a way to spend less time in my interrupt routine. Currently, the peripheral is configured to jump to the interrupt routine as soon as it receives one new character in the UART feed. Suggestions anyone? //Initialization char U1RX_data

Control USART RTS pin from driver on embedded board

由 淺唱寂寞╮ 提交于 2019-12-13 16:06:42
问题 This question was migrated from Unix & Linux Stack Exchange because it can be answered on Stack Overflow. Migrated 5 months ago . I'm porting the lirc_serial kernel module to work on our embedded board. We only need to implement the IR transmitter function. For only the transmitter, the custom driver need only control the RTS pin on /dev/ttyS0 , from within the module. On standard hardware, the driver loads: 00:05: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A NEW APPROACH I

HAL_UART_Transmit_IT: only a few bytes are sent

由 你。 提交于 2019-12-13 09:35:52
问题 i've got a problem on my STM32F407 with FreeRTOS. So Far most of the messages to a xbee module are sent. Only Sometimes (after 5 to 60 minutes) the TX process will be interrupted. In the debug session i can see, that TXEIE ist not set anymore after the 2 bytes (of ~40). Also the TxXferCount of the UART_HandleTypeDef is 42 (TxXferSize: 44). The flag TXE in SR-Register ist set but the TXEIE in CR1-Register not. The ISR was active for 2 times to store them into data/shift registers. This i can

Android Things 5.1 - 9 bit UART

由 偶尔善良 提交于 2019-12-12 19:45:52
问题 I'm trying to support 9-bit UART using Android Things, When I try to set the data size to 9 I receive IO exception. The only configurations that works are 7 and 8 bits. I know that is possible to make 9-bit emulation using the parity error interrupt, but on android things, I don't receive any handler of it. I tried also to set it using the native library, same exception. Is there a chance to have this interrupt? I'm using Pico-Pi iMX7D. I don't understand why there is no high-level support of
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