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Hardware Description
3-10
Copyright © ARM Limited 2000. All rights reserved.
3.3.3
Hardware reset
A hardware reset can be triggered from one of three sources:
•
a push button switch attached to a 2-pole connector JP17
•
push button switch in the keyboard housing panel
•
a debug system, such as Multi-ICE, connected to the JTAG test connector
The EconoReset monitors its output for the assertion of any of these momentary-action
switches. It provides switch debouncing by holding this output for a 350ms delay after
the switch is released.
3.3.4
Software reset
A software reset is initiated by setting the software reset (SWR) bit in the SA-1100
Reset controller Software Reset Register (RSRR). Reset is applied to most of the
internal circuitry of the SA-1100, and
CPU_nRESET_OUT
asserted. DRAM contents
are retained during this reset because DRAM refresh and configuration settings are not
cleared. The SA-1100 remains in reset for 256 processor clock cycles before it reboots.
3.3.5
Watchdog reset
The watchdog reset is triggered when the watchdog timer is enabled and the timer
expires. In all other respects it is identical to the software reset described above, except
that it sets the WDR bit in the RCSR.
3.3.6
Sleep reset
Sleep reset is invoked when the SA-1100 enters sleep mode, either by software setting
the force sleep bit in the power manager control register or by a power supply fault.
CPU_RESET_OUT
is asserted, and the DRAMs placed in self refresh mode.
Содержание Prospector P1100
Страница 1: ...ARM DUI 0122A Prospector P1100 User Guide ...
Страница 4: ...iv Copyright ARM Limited 2000 All rights reserved ARM DUI 0122A ...
Страница 86: ...Hardware Description 3 54 Copyright ARM Limited 2000 All rights reserved ARM DUI 0122A ...
Страница 140: ...Connector reference A 18 Copyright ARM Limited 2000 All rights reserved ARM DUI 0122A ...