ARM ARM DUI 0224I Computer Hardware User Manual


 
Hardware Description
3-22 Copyright © 2003-2007 ARM Limited. All rights reserved. ARM DUI 0224F
3.3 Reset controller
The reset controller initializes the ARM926EJ-S PXP Development Chip, the FPGA,
and external controllers as a result of a reset. The PB926EJ-S can be reset from the
following sources:
power failure
reset button
PCI backplane
•Logic Tiles
•JTAG
software.
Note
Use the RESET pushbutton (nPBRESET), the JTAG reset signal (nSRST), the PCI
backplane reset signal (P_nRST), the Logic Tile reset signal (nSYSPOR or nSRST
from the tile), or a software reset to reset the ARM926EJ-S core. The current
ARM926EJ-S PXP Development Chip configuration settings are retained. (The effect
of these reset sources pushbutton can be modified by setting the reset level flags, see
Reset level on page 3-24.)
Use the DEV CHIP RECONFIG pushbutton to reset the processor and reload the chip
configuration settings from the FPGA configuration registers.
Use the FPGA CONFIG pushbutton to reload the FPGA image without repowering the
entire system. The FPGA configuration registers are reloaded with their default values.
(Pressing FPGA CONFIG also resets the core and reloads the Logic Tile images.)
3.3.1 Reset and reconfiguration logic
Figure 3-11 on page 3-23 shows the reset and reconfigure logic. (Not all JTAG reset
signals are shown.)