SPRS565D April 2009 – June 2014 TMS320C6743
PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
A power-on reset (POR) is required to place the device in a known good state after power-up. Power-On Reset is initiated by bringing RESET and TRST low at the same time. POR sets all of the device internal logic to its default state. All pins are tri-stated with the exception of GP7[14]. During reset, GP7[14] is configured as a reserved function, and its behavior is not guaranteed; the user should be aware that this pin will drive a level, and in fact may toggle, during reset.
While both TRST and RESET need to be asserted upon power up, only RESET needs to be released for the device to boot properly. TRST may be asserted indefinitely for normal operation, keeping the JTAG port interface and device's emulation logic in the reset state.
.TRST only needs to be released when it is necessary to use a JTAG controller to debug the device or exercise the device's boundary scan functionality. Note: TRST is synchronous and must be clocked by TCK; otherwise, the boundary scan logic may not respond as expected after TRST is asserted.
.RESET must be released only in order for boundary-scan JTAG to read the variant field of IDCODE correctly. Other boundary-scan instructions work correctly independent of current state of RESET. For maximum reliability, the device includes an internal pulldown on the TRST pin to ensure that TRST will always be asserted upon power up and the device's internal emulation logic will always be properly initialized.
JTAG controllers from Texas Instruments actively drive TRST high. However, some third-party JTAG controllers may not drive TRST high but expect the use of a pullup resistor on TRST. When using this type of JTAG controller, assert TRST to intialize the device after powerup and externally drive TRST high before attempting any emulation or boundary scan operations.
A summary of the effects of Power-On Reset is given below:
CAUTION
A watchdog reset triggers a POR.