Hardware Description
ARM DUI 0447J
Copyright © 2009-2014, ARM. All rights reserved.
2-8
ID052914
Non-Confidential
2.2.4
External reset requests from the daughterboards
Either daughterboard can issue an external reset request to the motherboard:
1.
An external reset is received from the JTAG connector,
nSRST
, on the CoreTile Express
daughterboard.
2.
The Daughterboard Configuration Controller asserts
CB_RSTREQ
to the MCC on the
motherboard. See
Figure 2-2 on page 2-6
.
3.
The MCC asserts the
CB_nRST
reset signal. Depending on the setting of
ASSERTNPOR
in
the generic configuration file
config.txt
,
CB_nPOR
might also be asserted.
Note
•
If
only
CB_nRST
is asserted, a soft reset is performed. The MCC and
Daughterboard Configuration Controller reset the devices in the system, but do not
perform a full re-initialization.
•
If only
CB_nPOR
is also asserted, a hard reset is performed. The MCC and
Daughterboard Configuration Controller perform a full re-initialization.
4.
The daughterboards and IO FPGA are reset.
5.
The MCC also releases
CB_nPOR
if it was specified in the configuration file.
MCC releases
CB_nRST
.
6.
The daughterboards enter the run state.
Note
No daughterboard configuration files are read as a result of an external JTAG reset. No
daughterboard re-configuration is performed.