SDTI
EPM
DAP
L4 EMU
L3 access
Debug emulation
Device
Trace
port
EMU
pin
sdti_clk
sdti_txd[3:0]
Serial
interface
Message
formating
Buffer
Registers
sdti-001
Public Version
www.ti.com
SDTI Module
27.3 SDTI Module
This section describes the SDTI in the device.
27.3.1 SDTI Overview
SDTI is a main component that implements system trace in the device. The SDTI is connected to the
L4_EMU and mapped to the EMU domain. L4_EMU is accessible by the MPU and the digital signal
processor (DSP).
shows the SDTI in the device.
Figure 27-8. SDTI in the Device
The SDTI provides real-time software tracing to device. It generates software messages, which are
encoded as defined in the custom protocol.
NOTE:
The custom protocol is not MIPI
®
compliant.
Messages are a way for software to export crucial information and thus provide a high level of visibility on
system behavior (task entry, procedures calls, system status, test signatures, and memory allocation); 256
message channels, which can be allocated between software components, are available.
Messages are exported to trace receivers through a serial interface.
SDTI has its own local, dedicated first in first out (FIFO) buffering to allow trace capabilities concurrent to
ETM trace captured in ETB.
SDTI implements only trace export from device to remote PC through an emulator box. There is no
receive path feature in the SDTI. A standard asynchronous serial port (UART, 8 data bits, 1 stop-bit, no
parity) can be used as a back-channel to send emulation related control requests and data back to device.
27.3.2 SDTI Environment
The trace interface has four trace data pins and one trace clock, as shown in
Table 27-26. SDTI Pins
Port
Width
I/O
Reset Value
Description
(1)
sdti_clk
1
O
1
Trace interface clock output
sdti_txd
4
O
0000
Trace interface data
(1)
I = Input; O = Output
3607
SWPU177N – December 2009 – Revised November 2010
Debug and Emulation
Copyright © 2009–2010, Texas Instruments Incorporated