Table of Contents
Advertisement
Flash ROM Address Map
3.3.2 XD Bus Device
The AlphaPC 164UX XD bus drives a NVRAM,RTC,and KBDC devices.
3.3.3 ISA Expansion Slots
One ISA expansion slot is provided for plug-in ISA peripheral (J10).
3.3.4 ISA I/O Address Map
Table 3–1 lists the AlphaPC 164UX ISA I/O space address mapping.
Table 3–1 ISA I/O Address Map
Range (hex)
060-060
064-064
1F0-1F7
2F8-2FE
378-37B
3F0-3F5
3F6-3F6
3F7-3F7
3F8-3FE
3.4 Flash ROM Address Map
The flash ROM is mapped to three regions of memory. Access to the first two
regions is RO. The first two regions provide the software necessary to initialize the
system and transfer execution to the next level of software. When power is turned
on, address ranges 0 to 00.00FF.FFFF and 0F.FC00.0000 to 0F.FFFF.FFFF are
enabled. After the system has been initialized, these two address ranges are disabled.
Byte mode is then enabled in the 21164 and 21174. Byte mode is the only way to
access the flash ROM in address range 87.C000.0000 to 87.FFFF.FFFF. 21164 byte
instructions LDBU and STB must be used to access this region. Any other
instruction will produce UNDEFINED results with the possibility of damaging the
flash ROM.
Functional Description
3–10
Usage
i8042 PRT
i8042 PRT
ATAPI
Serial port—COM2
Parallel Port—LPT2
Floppy
ATAPI
Floppy
Serial port—COM1
Advertisement
Table of Contents
