Jtag-Reset Trst; Self-Reset On Tqmls1028A Revision 01Xx; Self-Reset On Tqmls1028A Revision 02Xx - TQ-Systems TQMLS1028A User Manual

4.2.1

JTAG-Reset TRST#

TRST# is coupled to PORESET#, as shown in the following Figure. See also NXP QorIQ LS1028A Design Checklist (5).
Figure 6: Block diagram TRST#
4.2.2

Self-Reset on TQMLS1028A revision 01xx

The following block diagram shows the RESET_REQ# / RESIN# wiring of the TQMLS1028A revision 01xx.
Figure 7: Block diagram RESET_REQ# / RESIN# TQMLS1028A revision 01xx
4.2.3

Self-Reset on TQMLS1028A revision 02xx

The LS1028A can initiate or request a hardware reset via software.
The output HRESET_REQ# is driven internally by the CPU and can be set by software by writing to RSTCR register (bit 30).
By default, RESET_REQ# is fed back via 10 kΩ to RESIN# on the TQMLS1028A. No feedback on the carrier board is required.
This leads to a self reset when RESET_REQ# is set.
Depending on the design of the feedback on the carrier board, it can "overwrite" the TQMLS1028A internal feedback and thus,
if RESET_REQ# is active, can optionally
•
trigger a reset
•
not trigger a reset
• trigger further actions on the base board in addition to the reset
RESET_REQ# is indirectly routed as signal RESET_REQ_OUT# to the connector (see Table 4).
"Devices" that can trigger a RESET_REQ# see TQMLS1028A Reference Manual (3), section 4.8.3.
User's Manual l TQMLS1028A UM 0101 l © 2020, TQ-Systems GmbH Page 9