GE VP11, Reference Manual

Page: 69 / 118

Real Time Clock
The RTC is a low-power clock that provides a time-of day clock and a 100-year
calendar with alarm features and battery backed operation. The time-of-day
function includes 14 control registers. Other features include maskable interrupt
sources and 242 bytes of general purpose CMOS RAM used by system BIOS.
Valid RAM data and time can be maintained after power down through the use
of an external battery source. The RTC is software compatible to the Dallas
DS1287, Motorola MC146818 and the Freescale equivalent.
Keyboard and Mouse
The communication between the PC and the keyboard and mouse is managed
by a USB connection. A legacy 8042 interface is available via emulation for
USB-unaware OS.
EIDE Interface
The VR11 offers two independent EIDE/ATAPI interfaces. Both interfaces are
logically connected to the primary PCI bus. Therefore a higher data transfer
rate is achievable. The signals of the primary EIDE interface are available at
the backplane IO connector only. The signals of the secondary EIDE interface
are used for connection of a 2.5'' HDD or Flash disk via connector P1800 on
board. The VR11 System BIOS automatically detects a connected EIDE HDD
or flash disk. At the primary EIDE interface, two hard disks can be connected.
In this case one HDD must be configured as master and the other one as slave.
Read the hard disk manual to find out where these jumpers are located on your
drive. The optional 2.5” onboard disk is connected to an onboard EIDE
connector (secondary EIDE interface).
Using EIDE and SCSI devices
: MS-DOS 6.22 can handle up to seven hard
disks at a time. The VR11 products allow the simultaneous use of EIDE and
SCSI hard disks. BIOS setup allows the re-ordering of the drives to boot from
either SCSI or EIDE drives.
Please note:
For correct operation of the EIDE interface, a maximum cable length of 12
inches (30 cm) must not be exceeded. For use with fast transfer rates such as
UDMA 66 and higher a high density 80 pole cable must be used. The use of
round wired cables is not recommended.
Serial Interface
The VR11’s serial ports are fully compatible with the NS16450 and NS16550.
This means that each serial interface provides a 16 byte FIFO and therefore
offers a higher performance than earlier used standard serial interfaces. The
UARTs have programmable baud rate generators capable of 50 to 115200
baud. There are four address locations defined for serial interfaces on standard
PCs. The two serial interfaces are I/O mapped and can occupy four address
ranges.
GE Intelligent Platforms – VR11, VP11 Hardware Reference Manual, Second Edition Page 69