ZHCSGV2J June 2009 – January 2017 OMAP-L138
PRODUCTION DATA.
The device target debug interface uses the five standard IEEE 1149.1(JTAG) signals (TRST, TCK, TMS, TDI, and TDO), a return clock (RTCK) due to the clocking requirements of the ARM926EJ-S and emulation signals EMU0 and EMU1.
TRST holds the debug and boundary scan logic in reset (normal DSP operation) when pulled low (its default state). Since TRST has an internal pull-down resistor, this ensures that at power up the device functions in its normal (non-test) operation mode if TRST is not connected. Otherwise, TRST should be driven inactive by the emulator or boundary scan controller. Boundary scan test cannot be performed while the TRST pin is pulled low.
PIN | TYPE | NAME | DESCRIPTION |
---|---|---|---|
TRST | I | Test Logic Reset | When asserted (active low) causes all test and debug logic in the device to be reset along with the IEEE 1149.1 interface |
TCK | I | Test Clock | This is the test clock used to drive an IEEE 1149.1 TAP state machine and logic.Depending on the emulator attached to , this is a free running clock or a gated clock depending on RTCK monitoring. |
RTCK | O | Returned Test Clock | Synchronized TCK. Depending on the emulator attached to, the JTAG signals are clocked from RTCK or RTCK is monitored by the emulator to gate TCK. |
TMS | I | Test Mode Select | Directs the next state of the IEEE 1149.1 test access port state machine |
TDI | I | Test Data Input | Scan data input to the device |
TDO | O | Test Data Output | Scan data output of the device |
EMU0 | I/O | Emulation 0 | Channel 0 trigger + HSRTDX |
EMU1 | I/O | Emulation 1 | Channel 1 trigger + HSRTDX |