12. Register Descriptions
270
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
MEM_IO
R/W
P1_RST
0
MEM_IO mode
PowerSpan II supports 4-byte reads. When this bit is set, I/O
commands to the corresponding image generates Memory
Read commands on the destination PCI bus (Py) with the
same byte enables latched from the source bus transaction. If
the destination of the transaction is the PB Interface, a
minimum 32-bit aligned, 4-byte read is generated on the
processor bus.
The MODE bit and the MEM_IO bit work together to control
the size of the transaction (see
0 = Regular IO mode
1 = Enables 4 byte reads on the processor (60x) bus or 1,2,3
or 4 byte memory reads on the PCI bus(es). The bus that the
read occurs on is controlled by the DEST bit.
RTT[4:0]
R/W
P1_RST
0b01010
Processor Bus Read Transfer Type (PB_TT[0:4])
Selects the Transfer Type on the Processor Bus. The register
bits RTT[4:0]/WTT[4:0] are mapped to pins PB_TT[0:4]
01010 = Read
GBL
R/W
P1_RST
0
Global
0 = Assert PB_GBL_
1 = Negate PB_GBL_
CI
R/W
P1_RST
0
Cache Inhibit
0 = Assert PB_CI_
1 = Negate PB_CI_
WTT[4:0]
R/W
P1_RST
0b00010
Processor Bus Write Transfer Type (PB_TT[0:4])
Selects the Transfer Type on the Processor Bus. The register
bits RTT[4:0]/WTT[4:0] are mapped to pins PB_TT[0:4]
00010 = Write with flush
PRKEEP
R/W
P1_RST
0
Prefetch Read Keep Data
Used to hold read data fetched beyond the initial PCI read
cycle. When set, subsequent read requests to the same
image at the next address retrieves the read data directly
from the Switching Fabric instead of causing the destination
bus to fetch more data. The read data is invalidated when a
read with a non-matching address occurs.
0 = Disable
1 = Enable
Name
Type
Reset
By
Reset
State
Function
Содержание PowerSpan II
Страница 8: ...Contents 8 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 14: ...List of Tables 14 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 18: ...About this Document 18 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 82: ...2 PCI Interface 82 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 112: ...3 Processor Bus Interface 112 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 156: ...7 Interrupt Handling 156 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 380: ...12 Register Descriptions 380 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 394: ...14 Package Information 394 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 414: ...15 AC Timing 414 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 416: ...16 Ordering Information 416 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 420: ...A Hardware Implementation 420 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 428: ...B Typical Applications 428 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 432: ...Glossary 432 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...