I2C 4 KB 記憶體目標¶

PxI2C4KbMemoryTarget 在 I2C(或 I3C)匯流排上模擬位元組定址記憶體裝置。控制器以 7 位元 I2C 位址 加上 16 位元記憶體偏移(子位址，MSB 在前)存取裝置，再讀寫連續位元組區塊。

當你要測試控制器驅動程式、EEPROM 風格週邊，或需要超過 8 位元定址的較大線性記憶體陣列時，這個目標很有用。

記憶體模型¶

4 KB 記憶體(0x0000–0x0FFF)。
建立時設定的 靜態 I2C 位址(例如 0x50)。
16 位元子位址 作為寫入交易的前兩個資料位元組送出(MSB 在前)，或在帶子位址的讀取序列之前寫入。

匯流排上典型寫入如下:

START → ADDR+W → SUB_ADDR_HI → SUB_ADDR_LO → DATA[0] → DATA[1] → … → STOP

典型帶子位址讀取如下:

START → ADDR+W → SUB_ADDR_HI → SUB_ADDR_LO → Sr → ADDR+R → DATA[0] → DATA[1] → … → STOP

Exerciser 在匯流排傳輸期間直接更新記憶體。Python 可透過 read_mem / write_mem 檢視或預載記憶體，不必經過 I2C 控制器。

快速開始¶

將目標掛載到 I2C 匯流排，並從 Python 讀寫記憶體:

from aqpxlib import AqProtocolExerciser
from aqpxlib.i2c import PxI2CBus, PxI2C4KbMemoryTarget

with AqProtocolExerciser.connect(port=60600) as px:
    i2c_bus = PxI2CBus(px, scl=0, sda=1)
    target = PxI2C4KbMemoryTarget(px, address=0x50)
    target.attach_to_bus(i2c_bus)

    target.write_mem(0x0100, [0x01, 0x02, 0x03, 0x04])
    assert target.read_mem(0x0100, 4) == [0x01, 0x02, 0x03, 0x04]

    target.detach_from_bus()

控制器存取¶

在同一條匯流排上使用 PxI2CController，以真實控制器的方式操作目標。將 16 位元子位址以兩個位元組的 list 傳給 i2c_write_addr / i2c_read_addr:

from aqpxlib import AqProtocolExerciser
from aqpxlib.i2c import PxI2CBus, PxI2CController, PxI2C4KbMemoryTarget

with AqProtocolExerciser.connect(port=60600) as px:
    i2c_bus = PxI2CBus(px, scl=0, sda=1)
    target = PxI2C4KbMemoryTarget(px, address=0x50)
    target.attach_to_bus(i2c_bus)

    i2c_controller = PxI2CController(px)
    i2c_controller.attach_to_bus(i2c_bus)

    sub_address = 0x0100
    data = [0xDE, 0xAD, 0xBE, 0xEF]

    i2c_controller.i2c_write_addr(
        address=target.address,
        sub_address=[(sub_address >> 8) & 0xFF, sub_address & 0xFF],
        data=data,
    )
    read_back = i2c_controller.i2c_read_addr(
        address=target.address,
        sub_address=[(sub_address >> 8) & 0xFF, sub_address & 0xFF],
        count=len(data),
    )
    assert read_back == data

    # 確認記憶體內容與控制器寫入的內容一致.
    assert target.read_mem(sub_address, len(data)) == data

    i2c_controller.detach_from_bus()
    target.detach_from_bus()

匯流排存取事件¶

當匯流排上其他裝置讀寫此目標時，exerciser 會在目標實例上發出 memory_target_write_event 與 memory_target_read_event。這些是共用事件型別(I3C、SPI 等其他記憶體目標也使用):

事件	Payload 欄位	發出時機
`memory_target_write_event`	`addr`, `data`	匯流排寫入傳輸完成後
`memory_target_read_event`	`addr`, `count`	匯流排讀取傳輸完成後

為每種事件型別分別訂閱處理函式:

from aqpxlib.event import PxEventMsg

@target.on_event("memory_target_write_event")
def on_memory_target_write(event: PxEventMsg):
    write = event.device_event.memory_target_write_event
    print(f"Bus write @ 0x{write.addr:04x}: {write.data.hex()}")

@target.on_event("memory_target_read_event")
def on_memory_target_read(event: PxEventMsg):
    read = event.device_event.memory_target_read_event
    print(f"Bus read @ 0x{read.addr:04x}, {read.count} bytes")

事件只反映匯流排活動。從 Python 呼叫 read_mem / write_mem 不會發出記憶體目標事件。

另見: 事件註冊與處理函式設定。

I3C 匯流排支援¶

PxI2C4KbMemoryTarget 可掛載到 I3C 匯流排(valid_buses 包含 "i3c" 與 "i2c")。裝置在 I3C SDA 線上以 I2C 風格目標運作。

API 參考¶

PxI2C4KbMemoryTarget ¶

PxI2C4KbMemoryTarget(
    exerciser: AqProtocolExerciser,
    address: int = 0,
    config: I2C4KbMemoryTargetConfig | None = None,
    *args,
    **kwargs
)

Bases: PxAbstractTarget

I2C byte-addressable 4 KB memory target.

Emulates a 4 KB memory device on an I2C or I3C bus. Controllers access memory using a 7-bit device address plus a 16-bit sub-address (MSB first).

Use read_mem and write_mem to access memory from Python. Bus reads and writes from a controller emit memory_target_read_event and memory_target_write_event notifications.

METHOD	DESCRIPTION
`add_event_handler`	Add an event handler to the current device instance.
`remove_event_handler`	Remove an event handler.
`get_event_handlers`	Retreive handlers registerd on this device.
`on_event`	Add an event handler to the instance by decorator.
`set_config`	Set the config of the target.
`detach_from_bus`	Detach the device from the bus.
`perform_operation`	Send an operation.
`attach_to_bus`	Attach the target to a bus.
`read_mem`	Read bytes from memory via the Protocol Exerciser API.
`write_mem`	Write bytes to memory via the Protocol Exerciser API.

ATTRIBUTE	DESCRIPTION
`available_events_map`	A reverse mapping of `field_name_by_number`, which uses field name as key. TYPE: `dict[str, str]`
`is_attached`	Check if the device is attached to a bus. TYPE: `bool`
`state`	Get the state of the device. TYPE: `Message \| None`
`name`	Get the name of the device. TYPE: `str`
`additional_data`	Get the opaque additional data blob associated with this device. TYPE: `bytes`
`config`	Get the config of the device. TYPE: `Message \| None`
`cts_op_name`	Get the name of CTS operation. Currently not available now. TYPE: `str \| None`
`address`	Static address of the device. TYPE: `int`

available_events_map ¶

available_events_map: dict[str, str]

A reverse mapping of field_name_by_number, which uses field name as key.

is_attached ¶

is_attached: bool

Check if the device is attached to a bus.

state ¶

state: Message | None

Get the state of the device.

name ¶

name: str

Get the name of the device.

additional_data ¶

additional_data: bytes

Get the opaque additional data blob associated with this device.

config ¶

config: Message | None

Get the config of the device.

cts_op_name ¶

cts_op_name: str | None

Get the name of CTS operation. Currently not available now.

address ¶

address: int

Static address of the device.

add_event_handler ¶

add_event_handler(event: str, handler: Callable[[Any], Any]) -> None

Add an event handler to the current device instance.

remove_event_handler ¶

remove_event_handler(event: str) -> None

Remove an event handler.

get_event_handlers ¶

get_event_handlers() -> dict[str, Callable]

Retreive handlers registerd on this device.

on_event ¶

on_event(event_type: str) -> Callable[[Callable[..., Any]], Callable[..., Any]]

Add an event handler to the instance by decorator.

set_config ¶

set_config(config: Message) -> None

Set the config of the target.

detach_from_bus ¶

detach_from_bus() -> None

Detach the device from the bus.

The opposite of the attach_to_bus method.

perform_operation ¶

perform_operation(operation: PxDeviceOperation) -> PxDeviceOperation

Send an operation.

attach_to_bus ¶

attach_to_bus(bus: PxAbstractBus) -> None

Attach the target to a bus.

This method is used to make the device aware of the bus it is connected to. It is used to set the bus attribute of the device.

Note

This method will not automatically create an actual instance on the Protocol Exerciser until user call the attach_to_bus method.

PARAMETER	DESCRIPTION
`bus` ¶	The bus to attach the device to TYPE: `PxAbstractBus`

RAISES	DESCRIPTION
`ValueError`	If the device is already attached to a bus

read_mem ¶

read_mem(addr: int, count: int) -> list[int]

Read bytes from memory via the Protocol Exerciser API.

This does not perform an I2C bus transaction. Use a PxI2CController to exercise the target over the bus.

PARAMETER	DESCRIPTION
`addr` ¶	Starting 16-bit memory address (`0x0000`-`0x0FFF`). TYPE: `int`
`count` ¶	Number of bytes to read. TYPE: `int`

RETURNS	DESCRIPTION
`list[int]`	Bytes read from memory as a list of integers (`0`-`255`).

write_mem ¶

write_mem(addr: int, data: list[int]) -> None

Write bytes to memory via the Protocol Exerciser API.

This does not perform an I2C bus transaction. Use a PxI2CController to exercise the target over the bus.

PARAMETER	DESCRIPTION
`addr` ¶	Starting 16-bit memory address (`0x0000`-`0x0FFF`). TYPE: `int`
`data` ¶	Bytes to write as a list of integers (`0`-`255`). Must fit within the 4 KB memory map. TYPE: `list[int]`

I2C 4 KB 記憶體目標¶

記憶體模型¶

快速開始¶

控制器存取¶

匯流排存取事件¶

I3C 匯流排支援¶

API 參考¶

PxI2C4KbMemoryTarget ¶

available_events_map ¶

is_attached ¶

state ¶

name ¶

additional_data ¶

config ¶

cts_op_name ¶

address ¶

add_event_handler ¶

remove_event_handler ¶

get_event_handlers ¶

on_event ¶

set_config ¶

detach_from_bus ¶

perform_operation ¶

attach_to_bus ¶

`bus` ¶

read_mem ¶

`addr` ¶

`count` ¶

write_mem ¶

`addr` ¶

`data` ¶

I2C 4 KB 記憶體目標¶

記憶體模型¶

快速開始¶

控制器存取¶

匯流排存取事件¶

I3C 匯流排支援¶

API 參考¶

PxI2C4KbMemoryTarget ¶

available_events_map ¶

is_attached ¶

state ¶

name ¶

additional_data ¶

config ¶

cts_op_name ¶

address ¶

add_event_handler ¶

remove_event_handler ¶

get_event_handlers ¶

on_event ¶

set_config ¶

detach_from_bus ¶

perform_operation ¶

attach_to_bus ¶

bus ¶

read_mem ¶

addr ¶

count ¶

write_mem ¶

addr ¶

data ¶

`bus` ¶

`addr` ¶

`count` ¶

`addr` ¶

`data` ¶