User`s guide

Introduction • 7
1.3.6 DMA
Two enhanced DMA controllers are provided on the cPCI-6765(A) for use by
the onboard peripherals. The cPCI-6765(A)'s DMA controllers reside in the
Intel 82371EB (PIIX4E) device.
1.3.7 Real-Time Clock
The real-time clock performs timekeeping functions and includes 256 bytes
of general purpose, battery-backed, CMOS RAM. Timekeeping features
include an alarm function, a maskable periodic interrupt, and a 100-year
calendar. The system BIOS uses a portion of this RAM for BIOS setup
information. The cPCI-6765(A)'s Real-Time Clock resides in the Intel
82371EB (PIIX4E) device.
1.3.8 Baseboard Management
The Zircon CP baseboard management controller is used to manage all
aspects of the system board. The features are summarized as follows.
• ARM7/TDMI controller with internal 14KB SRAM
• IPMB interface
• External 16-bit flash ROM interface with ROM size 2Mb to 8Mb
• Six channels A-to-D converter for voltage monitoring, 10-bit resolution
• Provide a heartbeat timer
• Support CPU internal instruction error input (IERR#)
• Support CPU floating point error input (FERR#)
QLogic provides a firmware suite supporting the Intelligent Platform
Management Interface (IPMI) specification, including the Intelligent Platform
Management Bus (IPMB). See appendix C for full details.
1.3.9 Power Ramp Circuitry
The cPCI-6765(A) features a power controller with power ramp circuitry to
allow the board's voltages to be ramped in a controlled fashion. The power
ramp circuitry eliminates any large voltage or current spikes caused by hot
swapping boards (See Appendix A for an in-depth detail of the Hot Swap
feature). This controlled ramping is a requirement of the CompactPCI Hot
Swap specification, PICMG 2.1, Version 1.0. The cPCI-6765(A)'s power
controller unconditionally resets the board when it detects that the 3.3V, 5V,
and 12V supplies are below an acceptable operating limit. These limits are
defined as 4.75V (5V supply), 3.0V (3.3V supply), and 10.0V (+12V supply).