AXI5Packet Class

The AXI5Packet class extends the base Packet class with AXI5-specific functionality. It uses generic field names that match the field configuration and supports all AXI5-specific features including atomic operations, memory tagging, chunked transfers, and poison indicators.

Key Differences from AXI4

• Removed fields: region (ARREGION/AWREGION)
• Added fields: atop, nsaid, trace, mpam, mecid, unique, tagop, tag, chunken, chunkv, chunknum, chunkstrb, poison, tagupdate, tagmatch
• Channel detection: Uses AXI5-specific field presence (e.g., atop for AW, chunken for AR) to determine channel type
• Protocol validation: Includes AXI5-specific validation for ATOP encoding, TAGOP values, and chunk rules

Class Signature

class AXI5Packet(Packet):
    def __init__(self, field_config, **kwargs)

Constructor Parameters

Parameter	Type	Description	Default
field_config	FieldConfig	Field configuration for the specific AXI5 channel	(required)
**kwargs	Any	Initial field values using generic names (id, addr, data, etc.)	--

Class Methods (Packet Factories)

create_aw_packet(id_width, addr_width, user_width, data_width, **field_values) -> AXI5Packet

Create a Write Address (AW) channel packet.

Parameter	Type	Description	Default
id_width	int	Width of ID field	8
addr_width	int	Width of ADDR field	32
user_width	int	Width of USER field	1
data_width	int	Data width for tag calculation	32
**field_values	Any	AW field values (id, addr, len, atop, tagop, etc.)	--

create_w_packet(data_width, user_width, **field_values) -> AXI5Packet

Create a Write Data (W) channel packet.

Parameter	Type	Description	Default
data_width	int	Width of DATA field	32
user_width	int	Width of USER field	1
**field_values	Any	W field values (data, last, strb, poison, tag, tagupdate)	--

create_b_packet(id_width, user_width, data_width, **field_values) -> AXI5Packet

Create a Write Response (B) channel packet.

Parameter	Type	Description	Default
id_width	int	Width of ID field	8
user_width	int	Width of USER field	1
data_width	int	Data width for tag calculation	32
**field_values	Any	B field values (id, resp, trace, tag, tagmatch)	--

create_ar_packet(id_width, addr_width, user_width, **field_values) -> AXI5Packet

Create a Read Address (AR) channel packet.

Parameter	Type	Description	Default
id_width	int	Width of ID field	8
addr_width	int	Width of ADDR field	32
user_width	int	Width of USER field	1
**field_values	Any	AR field values (id, addr, len, chunken, tagop, etc.)	--

create_r_packet(id_width, data_width, user_width, **field_values) -> AXI5Packet

Create a Read Data (R) channel packet.

Parameter	Type	Description	Default
id_width	int	Width of ID field	8
data_width	int	Width of DATA field	32
user_width	int	Width of USER field	1
**field_values	Any	R field values (id, data, resp, last, poison, chunkv, chunknum, etc.)	--

Instance Methods

get_channel_type() -> str

Determine which AXI5 channel this packet belongs to based on field presence.

Returns: 'AW', 'W', 'B', 'AR', 'R', or 'UNKNOWN'

validate_axi5_protocol() -> Tuple[bool, str]

Validate the packet against AXI5 protocol rules.

Checks performed: - Burst length range (0-255) - Burst size range (0-7) - Burst type validity (0, 1, 2) - ATOP encoding validity (AW channel) - TAGOP range (0-3) - Response code validity (B, R channels) - Chunk field consistency (R channel) - WLAST / RLAST presence

Returns: Tuple of (is_valid, error_message) where error_message is empty if valid.

get_burst_info() -> Dict[str, Any]

Get burst information from address packets (AW/AR).

Returns: Dictionary with keys: burst_type, burst_length, burst_size, bytes_per_beat, total_bytes, address. Returns empty dict for non-address packets.

get_response_info() -> Dict[str, Any]

Get response information from response packets (B/R).

Returns: Dictionary with keys: response_code, response_name, is_error, is_exclusive, tagmatch. For R channel, also includes is_last, poison, chunkv, chunknum. For B channel, also includes trace.

get_axi5_features() -> Dict[str, Any]

Get AXI5-specific feature information from the packet.

Returns: Dictionary with feature status including: - is_atomic, atomic_type -- atomic operation info - tagop, tag, tagmatch, tagupdate -- MTE info - nsaid, mpam, mecid -- security context - trace -- tracing status - unique -- unique access - chunken, chunkv, chunknum, chunkstrb -- chunking info - poison -- poison indicator

Convenience Functions

create_simple_write_packets(id_val, addr, data, id_width, addr_width, data_width) -> Tuple[AXI5Packet, AXI5Packet]

Create AW and W packets for a simple single-beat write.

create_simple_read_packet(id_val, addr, id_width, addr_width) -> AXI5Packet

Create an AR packet for a simple single-beat read.

create_atomic_write_packets(id_val, addr, data, atop, id_width, addr_width, data_width) -> Tuple[AXI5Packet, AXI5Packet]

Create AW and W packets for an atomic operation.

Parameter	Type	Description
atop	int	Atomic operation type: 0x10=Store, 0x20=Load, 0x30=Swap, 0x31=Compare

create_tagged_write_packets(id_val, addr, data, tag, tagop, id_width, addr_width, data_width) -> Tuple[AXI5Packet, AXI5Packet]

Create AW and W packets with Memory Tagging Extension support.

Parameter	Type	Description
tag	int	Memory tag value
tagop	int	Tag operation: 0=Invalid, 1=Transfer, 2=Update, 3=Match

Packet Utility Functions

The axi5_packet_utils module provides additional helper functions:

Address Packets

• create_simple_read_packet(address, id_val, burst_len, size, burst_type, **kwargs) -- AR packet
• create_simple_write_address_packet(address, id_val, burst_len, size, burst_type, **kwargs) -- AW packet

Data Packets

• create_simple_write_data_packet(data, last, strb, data_width, **kwargs) -- W packet
• create_simple_read_response_packet(data, resp, last, id_val, data_width, **kwargs) -- R packet
• create_simple_write_response_packet(resp, id_val, **kwargs) -- B packet

Burst Packets

• create_burst_write_packets(id_val, start_addr, data_list, size, burst_type, **kwargs) -- AW + W list
• create_burst_read_response_packets(id_val, data_list, resp, **kwargs) -- R list

AXI5-Specific Packets

• create_atomic_transaction_packets(id_val, addr, data, atop, data_width, **kwargs) -- Atomic AW + W
• create_tagged_write_packets(id_val, addr, data_list, tag, tagop, data_width, **kwargs) -- MTE AW + W list
• create_tagged_read_packet(id_val, addr, burst_len, tagop, **kwargs) -- MTE AR
• create_chunked_read_packet(id_val, addr, burst_len, **kwargs) -- Chunked AR
• create_secure_write_packets(id_val, addr, data, nsaid, mpam, mecid, data_width, **kwargs) -- Security AW + W
• create_traced_write_packets(id_val, addr, data, data_width, **kwargs) -- Traced AW + W

Usage Examples

Example 1: Creating and Validating Packets

from CocoTBFramework.components.axi5 import AXI5Packet

# Create an AW packet with atomic operation
aw = AXI5Packet.create_aw_packet(
    id=1, addr=0x1000, len=0, size=2, burst=1, atop=0x30
)
print(aw)  # "AXI5Packet(AW: id=1, addr=0x1000, len=0, atomic=AtomicSwap)"

# Validate protocol compliance
is_valid, errors = aw.validate_axi5_protocol()
assert is_valid, f"Protocol errors: {errors}"

# Get AXI5-specific feature info
features = aw.get_axi5_features()
assert features['is_atomic'] is True
assert features['atomic_type'] == 'AtomicSwap'

Example 2: Working with MTE Packets

from CocoTBFramework.components.axi5 import (
    create_tagged_write_packets, create_tagged_read_packet
)

# Create tagged write (MTE)
aw_pkt, w_pkts = create_tagged_write_packets(
    id_val=2, addr=0x3000,
    data_list=[0x11111111, 0x22222222],
    tag=0xA, tagop=2  # Update operation
)

# Create tagged read
ar_pkt = create_tagged_read_packet(
    id_val=3, addr=0x3000, burst_len=2, tagop=1  # Transfer operation
)

Example 3: Security and Tracing Packets

from CocoTBFramework.components.axi5 import (
    create_secure_write_packets, create_traced_write_packets
)

# Write with security context
aw_sec, w_sec = create_secure_write_packets(
    id_val=4, addr=0x5000, data=0xABCDEF01,
    nsaid=2, mpam=0x100, mecid=0x1234
)

# Write with tracing enabled
aw_trace, w_trace = create_traced_write_packets(
    id_val=5, addr=0x6000, data=0xFEEDFACE
)