Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 7/19/2024
Public
Document Table of Contents

5.8.6.5.7.3. Short Data Argument Data Structure

Short data argument data structure is used to provide payload-related information for the TX transfers when the payload size is less than or equal to 3 bytes.

Table 249.  Short Data Argument Data Structure
BIT-FIELD FIELD NAME WIDTH DESCRIPTION
31:23 DATA_BYTE_2 8

Data Byte -2

This field is used for storing the data byte -2.

23:16 DATA_BYTE_1 8

Data Byte -1

This field is used for storing the data byte -1.

15:8

DATA_BYTE_0/DB

8

Data Byte -0/Defining Byte

This field is used for storing the data byte -0.

DB indicates the 8-bit defining byte to be transferred in the CCC transfer. This byte is valid only when both CP and DBP bits are enabled, otherwise the controller ignores this byte.

Note: When defining byte (DBP) is enabled in short data argument,
  • 1. The BYTE_STRB[0] bit is treated to be always enabled whether or not you set it.
  • 2. The maximum possible payload bytes to be sent is ‘2’ due to the first byte being occupied by the defining byte.
7:6 RESV 2 Reserved
5:3 BYTE_STRB 3

Byte Strobe

This field is used to select the valid data bytes of the short data argument.

  • BYTE_STRB[0] - Data Byte -0 Valid Qualifier
  • BYTE_STRB[1] - Data Byte -1 Valid Qualifier
  • BYTE_STRB[2] - Data Byte -2 Valid Qualifier

Valid combinations = 3'b001, 3'b011, and 3'b111

2:0 CMD_ATTR 3

Command Attribute

Defines the command type and its bit-field format.

  • 0: Transfer command
  • 1: Transfer argument
  • 2: Short data argument
  • 3: Address assignment command
  • 4-7: Reserved