Using 3 UART interfaces

Owned by Edmund Bendels (Deactivated)
Last updated: 2021-12-06 by Jin ZhaoVersion comment
2 min read
Q

I would like to use all 3 UARTs of netX 90 im my application.

How can I "tell" the COM-side not to use the shared UART because it is used by the APP-side?

A

netX 90 features 3 UARTs

  1. UART_APP (dedicated to APP-side, can be used by ARM Cortex-M4 CPU)
  2. UART_XPIC (dedicated to APP-side, can be used by ARM Cortex-M4 CPU)
  3. UART_SHARED - console interface (can be used by APP and COM side)

The COM-side use the shared UART only in in two cases

a) in console mode

b) when the Marshaller is enabled in the COM-side firmware (default)

I.e. if the shared UART shall be used by the APP-side, the Marshaller must be disabled in the COM-side firmware.
This can be done with the "tag list editor" utility, which is part of netXSTUDIO.
Disable the UART Diagnostic Interface (but keep the tag itself enabled)

In addition, the UART_SHARED must be assigned to the netX 90 APP inside the Firewall settings of the hardware configuration.
Open the hardware config file and the "General Configuration" Dialog.
In the General Configuration dialog, set “Shared UART Firewall" to "APP has read/write access, COM has no access”.
By default, the setting is “COM has read/write access, APP has no access”


Console mode is a special mode for e.g. flash programming. The APP-side is not running in console mode. In normal operation, console mode is not active.

UART-XPIC can be freely used by the ARM Cortex-M4 CPU on APP-side.

All three UARTs are supported by the Hilscher Peripheral Driver.

The UART_SHARED is assigned to fixed pins, UART_APP amd UART_XPIC can be assigned to any MMIO pin and to dedicated pins at the HIF pin group (please refer to the diagram below)
On the evaluation board NXHX 90-JTAG, the UART_SHARED is connected to a) pin header X902, b) the FDTI chip, using switch S701 the user can choose which option is enabled a) or b)
When UART_SHARED is routed to the FTDI chip, it is possible to use a USB cable and a virtual COM port on a PC to communicate with netX.
When UART_SHARED is routed to X902, typically the RS232 driver adapter board “NXHX-RS232” is required in addition.

Please refer to the NXHX 90-JTAG Manual for further details.


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