SDTI
sdti_clk
sdti_txd[3:0]
Serial
interface
Target
interface
Registers
sdti-008
Message
formatting
and
compression
Test
pattern
generator
FIFO
Clock
generator
full
empty
L4
Public Version
SDTI Module
www.ti.com
27.3.4 SDTI Functional Description
27.3.4.1 SDTI Block Diagram
is a block diagram of the SDTI.
Figure 27-15. SDTI Block Diagram
The SDTI is configured through the L4 EMU target interface.
All SDTI registers are 32-bit (double word) aligned. For information about handling non-aligned addresses,
supported/not supported byte enables, access to nonexistent memory address, reads to write-only
registers, and writes to read-only registers, see
, SDTI Error Handling.
The SDTI is active (enabled) when enabled through claim procedure. For information about the claim
procedure, see
, SDTI Ownership. When enabled, SDTI generates messages or test
patterns and exports them through the serial interface.
27.3.4.2 SDTI Ownership
Some SDTI resources can be owned by the application or by the debugger. Ownership is required to
configure or program the SDTI. Ownership determines whether write access is granted to the SDTI
configuration registers. SDTI resource ownership is exclusive. Hence, simultaneous use of SDTI
resources by both debugger and application is not permitted. However, the debugger can forcibly seize
ownership of SDTI resources.
NOTE:
Read access does not require ownership; therefore, either party can read any SDTI register
with or without ownership.
The application and the debugger cannot simultaneously write to the following SDTI resources (also called
units):
Window control register (accompanied by the serial configuration register and the test control register)
27.3.4.2.1 Ownership States
Ownership has three basic states:
•
Available: The unit has not been claimed.
•
Claimed: The unit has been claimed.
•
Enabled: The unit is enabled by the owning party.
27.3.4.2.1.1 Available State
The SDTI is set to available state when one of two conditions occurs:
•
The state is available when POR is asserted.
•
The state is available if the SDTI is owned by the debugger and the emulator is disconnected.
3612
Debug and Emulation
SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated