PORz
Internal Chip Resetn
Warm reset source
assertion
High frequency system input clock
External warm reset assertion
detected on the nRESETIN_OUT pin
Warm reset out driven
on nRESETIN_OUT pin
Duration defined by
PRCM.
PRM_RSTTIME
[7:0]
RSTTIME1
Duration defined by
PRCM.
PRM_RSTTIME
[12:8]
RSTTIME2
EMIF FIFO
drains and
DRAM is put
in self-refresh
Maximum
50 cycles
Tri-stated with
weak pullup
CLK_M_OSC
Power, Reset, and Clock Management
This output will remain asserted as long as PRCM keeps reset to the host processor asserted.
Note: TRST does not cause RSTOUTn assertion
8.1.7.4.1.2 Warm Reset Sequence
1. nRESETIN_OUT pin at chip boundary gets asserted (goes low). NOTE: For Warm Reset sequence to
work as described, it is expected that PORz pin is always inactive, otherwise you will get PORz
functionality as described in previous section.
2. All IOs (except test and emulation) will go to tri-state immediately.
3. Chip clocks are not affected as both PLL and dividers are intact.
4. nRESETIN_OUT gets de-asserted after 30 cycles
5. PRCM de-asserts reset to the host processor and all other peripherals without local CPUs.
6. Note that all IPs with local CPUs will have local reset asserted by default at Warm Reset and reset de-
assertion would require host processor to write to respective registers in PRCM.
shows the nRESETIN_OUT waveform when using nRESETIN_OUT as warm reset source.
For the duration when external warm reset switch is closed, both the device and chip will be driving zero.
Figure 8-21. Warm Reset Sequence (External Warm Reset Source)
shows the nRESETIN_OUT waveform when any one of the warm reset sources captured
except using nRESETIN_OUT itself as warm reset source.
539
SPRUH73H – October 2011 – Revised April 2013
Power, Reset, and Clock Management (PRCM)
Copyright © 2011–2013, Texas Instruments Incorporated