Adaptec SlimSCSI APA-1460, Техническое описание

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5-3
Functional Specification
APA-1460 SlimSCSI Technical Reference
Stock Number: 510671-00, Rev. A
Page: 5-3
Print Spec Number: 492966-00, Rev. A
Current Date: 8/22/94
ECN Date: 8/30/94
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Functional Specification
Functionally, the APA-1460 responds to two types of PCMCIA bus cycles, Attribute Mem-
ory Space read/write cycles (configuration) and I/O cycles (SCSI protocol controller
access).
PCMCIA Attribute Memory Space
PCMCIA cards were originally memory add-in cards only. As such, certain
PCMCIA terminology is geared toward memory devices (e.g., ROM/RAM). The Attribute
Memory Space is a read/write address space, which in the PCMCIA Specification, may be
as large as 64 MBytes. The APA-1460 only decodes the first 16 KBytes of this address space
(address lines above A13 are ignored). The primary purpose of the Attribute Memory
Space is to provide a separately addressable region on each PCMCIA add-in card which is
dedicated to configuration functions. Both memory (typically read-only) and memory-
mapped registers reside in this space.
The APA-1460 decoding of the Attribute Memory Space is shown in the table below:
The Attribute Memory ROM (including the CIS) and the Configuration Option Register
are discussed further in the following two sections.
APA-1460 CIS
There is an 8 KByte ROM on the APA-1460. Currently, only the first few hundred bytes of
this ROM are actually used. This small amount of memory is all that is required to store
the APA-1460 CIS as discussed in the next paragraph.
The PCMCIA Specification defines a card metaformat. This metaformat defines a set of struc-
tures to be read through the Attribute Memory Space which define certain configuration
information pertinent to the add-in card. A master structure, which contains this set of
structures, is the CIS. The key information stored in the APA-1460 CIS is listed below:
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Manufacturer: "Adaptec, Inc"
■
Product: "APA-1460 SCSI Host Adapter"
■
Version: "Version 0.01"
■
Device Speed: 250 ns/cycle
■
Configuration
Register Base Address: 2000h
■
I/O Space Description: 16-bit, 10 I/O address lines used, 2 ranges
(actually, 8 ranges are possible, only 4 are defined)
Address Range Function Access
0 - 1FFFh Attribute Memory ROM (CIS) Read-only
2000 - 3FFFh Configuration Option Register Read/Write
4000h Reserved n/a