LTPI

The LTPI (LVDS Tunneling Protocol & Interface) is an interface designed for transferring low-speed signals between the HPM (Host Platform Manager) and SCM (Secure Control Module).

It supports GPIO, I²C / SMBus, and UART channels, and achieves multi-channel multiplexing through TDM (Time-Division Multiplexing) over an LVDS link.

The GPIO channel includes two types — low latency and normal latency; the I²C / SMBus channel handles single-controller links; the UART channel supports flow control; the OEM channel is reserved for proprietary interfaces; and the Data channel supports memory-mapped data transfer.

LTPI Measurement Solution

BF7264 Pro with LTPI Solution + LVDS POD

BF7264 Pro

BF7264 Pro Specifications PDF

LTPI Solution

LVDS POD

LVDS POD Specifications PDF

LTPI Solution (Analyzer Mode)

LTPI solution specifications:

• – Supports LTPI (LVDS Tunneling Protocol & Interface) as defined in OCP DC-SCM 2.0, including SDR and DDR transfer modes
• – Analyzes LTPI links up to 1.2 Gbps
• – Real-time frame decode: comma (K28.5 / K28.6 / K28.7) alignment, frame type / subtype classification, CRC-8 check with error marking
• – Frame Report lists Tx / Rx frames with full field decode in table form
• – Tunneled Report reconstructs the channel contents: complete I2C transactions (Start / address / R/W / ACK / data / Stop), GPIO bit changes and UART bytes, with Combined / Separate view modes
• – Statistics by Tx / Rx / Error with click-to-jump to the corresponding frame
• – Waveform view shows the four LTPI channels together with the decoded result
• – LTPI trigger: CRC error, symbol error or disparity error, or a Tx / Rx data pattern up to 16 bytes; the comma character is selectable on the settings page
• – OEM / Vendor custom fields via AqLTPI_Vendor.csv (field name, bit range, enumerations, engineering-unit scaling)
• – 32 Gb RAM with disk streaming for long captures
• – Search and Filter functions

Frame Report

Lists Tx / Rx frames in time order with frame type, subtype, CRC check result and full field decode; clicking a row shows the 16 raw bytes and a field-by-field breakdown in the detail pane.

Tunneled Report

Reconstructs the tunneled channels: complete I2C transactions on channels 0–5 (Start / address / R/W / ACK / data / Stop), GPIO bit changes (both low-latency LL and normal-latency NL classes), and UART byte reconstruction on channels 0–1 including RTS / CTS flow-control events; offers Combined (merged with the Frame Report) and Separate views.

Statistics

Accumulates frame counts by Tx / Rx / Error with per-type and per-subtype breakdown; errors are further classified as CRC, Symbol, Disparity and Incomplete; clicking an entry jumps to the corresponding frame.

LVDS POD (LA Mode)

8b10b

LTPI Packet, including command decoding

GPIO / I2C / UART Packet

Save as TXT/CSV

In Logic Analyzer mode, click the icon above the report area to save the decoded data as a TXT/CSV file.

LTPI Decoding Setup Steps

1. Click Quick Settings or Add Protocol Decode to select a protocol for logic analyzer capture.

2. Select LTPI for decoding.

3. If you use Quick Settings, the system will recommend configurations for trigger type, sampling rate, voltage threshold, and channel settings.

4. Click the icon to access the Decode Settings screen.

Decode Settings

Assign the test signals of the DUT to the corresponding logic analyzer channels:

Tx Clock

Tx Data

Rx Clock

Rx Data

SDR: The DUT transmits signals in Single Data Rate mode.

DDR: The DUT transmits signals in Double Data Rate mode.

Waveform: Displays the direction (Transmit / Receive) and the decoded content — 8b10b / LTPI / GPIO / UART / I²C.

Detail Report: Enable or disable detailed reporting.

Import GPIO CSV: Enable importing bit names for GPIO signals.

[LL0] indicates the bit name mapping for Low Latency GPIO-0 (bits 7–0).

[LL1] indicates the bit name mapping for Low Latency GPIO-1 (bits 7–0).

[NL0] indicates the bit name mapping for Normal Latency GPIO-0 (bits 7–0).

[NL1] indicates the bit name mapping for Normal Latency GPIO-1 (bits 7–0).