ProSoft Technology PC56-OPC - Manual (Page 17)

Reset, Auxiliary Timers and PCI Information PC56 ♦ ControlLogix Platform
User Manual In-Rack Industrial PC
ProSoft Technology, Inc.
Page 17 of 34
November 18, 2009
4 Reset, Auxiliary Timers and PCI Information
In This Chapter
™ Overview ...............................................................................................17
™ Using the USB Ports .............................................................................18
4.1 Overview
In addition to the standard PC system hardware, PC56 contains the ControlLogix
back plane interface circuitry with 512 MB SDRAM (upgradeable to 1 GB), an
82C54 timer, 512KBytes of battery-backed SRAM and a four character alpha-
numeric display.
This chapter describes the functionality of the special hardware contained in the
PC56 system.
4.1.1 Auxiliary Timer (WinCE Only)
The 82C54 timer shares a single PCI interrupt with the backplane support
hardware, therefore your software must support sharing of this interrupt if you are
going to use the timer in an application requiring the timer to initiate an interrupt.
The 82C54 timer can also be configured to use the Non-Maskable Interrupt
instead of a PCI interrupt. When the timer is configured to use NMI, then interrupt
sharing between the timer and back plane hardware is not required..
4.1.2 RESET: Functional Description
A hardware reset occurs when the PC56 is powered up or when the reset switch
is depressed. When a hardware reset occurs, the ControlLogix interface circuitry
is reset, and its interrupt is disabled. The 82C54 timer interrupt is also disabled.
4.1.3 PCI Configuration Base Addresses
The PCI configuration space contains the addresses allocated to the shared
RAM of the ControlLogix
® interface circuitry and the SRAM as well as other PCI
relevant addresses. The Vendor ID = 167Ch and Device ID = 0001h.
4.1.4 Four Character Alpha-Numeric Display
One of the unique features of PC56 is the front panel four character
alphanumeric display. This display can scroll ASCII messages or display simple
error codes. Refer to the API manual for information on how to write to this
display.