3. Processor Bus Interface
99
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
•
Data Valid (PB_DVAL_): This signal is asserted by the PB slave to indicate the successful transfer
of an 8-byte quantity within an extended transfer of 16 or 24 bytes. PB_TA_ is asserted together
with PB_DVAL_ on the transfer of the last 8-byte quantity.
•
Transfer Error Acknowledge (PB_TEA_): This signal indicates an unrecoverable error and causes
the external master to immediately terminate the data tenure.
3.3.3.2
Assertion of PB_TEA_
PowerSpan II asserts PB_TEA_ when a particular slave image cannot handle transactions involving
more than 4 bytes. This applies to the following:
•
)
•
accesses to general purpose slave image configured for PCI I/O space
•
access to registers designed to generate PCI Configuration or IACK commands (see
“Configuration and IACK Cycle Generation” on page 246
PowerSpan II also asserts PB_TEA_ if a read from PCI generates a Master-Abort or Target-Abort.
The assertion PB_TEA_ is enabled or disabled with the TEA Enable (TEA_EN) bit in the
Bus Miscellaneous Control and Status Register” on page 304
3.3.3.3
Errors
The PowerSpan II PB Slave detects the following error conditions:
•
address parity
•
data parity on writes
•
illegal accesses
and
“Interrupt Handling” on page 145
for a full description of error
logging support and associated interrupt mapping options.
The PB Slave does not assert a data termination signal earlier than the
address retry window
.
In a development environment, the TEA_EN bit is set to allow the assertion of PB_TEA_ to
support the debug of software. In a production environment, customers may find it useful to
disable the assertion of PB_TEA_.
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 ...