UDP Formatter Sub-Block
=======================

The UDP Formatter Sub-Block is a communication-interface sub-block that provides the microcontroller with access to status, diagnostic, and configuration information for a UDP connection on the board.

As described in the corresponding section, the position of this sub-block depends on the ordering of preceding blocks and on the size of the Hardware Interfaces block. Consequently, the base address of this sub-block is parameter-dependent. In this document, all register addresses are specified relative to an offset.

Sub-Block header
----------------

The sub-block starts with a constant (CONST) header containing:

* an 8-bit identifier for this sub-block type; and
* an 8-bit field indicating optional features available in this sub-block.

For this sub-block, no optional features are defined; therefore, the feature field is reserved. The sub-block ID is ``3``.

.. regtreedoc::
  :file: ./source/design/Architecture/CommunicationsSubBlocks/UDPFormatterSubBlock.json
  :register: ["Sub-block header"]
  :addressoverride: Offset + 0x0000

Status register
---------------

The UDP Formatter Sub-Block provides a status register from which diagnostic indicators describing the current state of the formatter can be read.

Any change in master status observed through this register shall be signaled by asserting the **Communication-interface status flag** in the **Interrupt register**.

.. regtreedoc::
  :file: ./source/design/Architecture/CommunicationsSubBlocks/UDPFormatterSubBlock.json
  :register: ["UDP Formatter status register"]
  :addressoverride: Offset + 0x0001

Diagnostics
-----------

The UDP Formatter Sub-Block includes two diagnostic registers exposed by the UDP Formatter module. These registers provide monitoring metrics for the microcontroller to supervise the UDP Formatter communication interface.

.. regtreedoc::
  :file: ./source/design/Architecture/CommunicationsSubBlocks/UDPFormatterSubBlock.json
  :register: ["Packets sent counter"]
  :addressoverride: Offset + 0x0002

.. regtreedoc::
  :file: ./source/design/Architecture/CommunicationsSubBlocks/UDPFormatterSubBlock.json
  :register: ["FIFO full error counter"]
  :addressoverride: Offset + 0x0003