Etm Environment - Texas Instruments OMAP5910 Technical Reference Manual

2.12 ETM Environment

2.12.1 ETM Features
2.12.2 ETM Interface
The OMAP5910 device has an embedded trace macrocell (ETM) to provide
instruction and data trace capabilities of the TI925T processor. ETM9 in large
configuration uses an 8-bit data output. The instruction trace shows the
instruction flow of the MPU. The data trace shows the data access results after
the MPU executes load and store operations.
The ETM has the following features:
-
Instruction/data trace
-
8-bit trace packet width
-
45-byte trace packet capture FIFO
-
Eight pairs of address comparators for trace trigger
-
Height comparators for trace trigger
-
Four 16-bit counters
-
3-state sequencer (state machine)
The ETM logical signal interface contains 13 trace interface pins and nine
JTAG interface pins. The ETM trace interface has the following signals:
-
TRACEPKT[0..7]
The TRACEPKT signals comprise the 8-bit data trace packets (packaged
address and data information).
-
PIPESTAT[0..2]
The PIPESTAT signals are used to output the MPU pipeline at the
MPU execute stage on every TRACECLK and are used by software to
reconstruct the compressed trace output.
-
TRACESYNC
The TRACESYNC signal is used to indicate when the first of multiple
packets are to be output on the TRACEPKT bus.
-
TRACECLK
The TRACECLK operates at one of two frequencies:
J
The same frequency as the MPU
J
The MPU frequency divided by two (half-rate clocking)
When this rate is selected, the trace port analyzer (TPA) samples
the trace data signals on both the rising and the falling edges of the
TRACECLK. Bit 13 of the ETM control register enables you to select
this rate.
ETM Environment
MPU Subsystem 2-75