Phase Mismatch Jump Registers
4-115
Registers: 0xD8–0xDA
SCSI Byte Count (SBC)
Read Only
SBC
SCSI Byte Count
[23:0]
This register contains the count of the number of bytes
transferred to or from the SCSI bus during any given
BMOV. This value is used in calculating the information
placed into the
and
registers and should not need to
be used in normal operations. There are two conditions
in which this byte count will not match the number of
bytes transferred exactly. If a BMOV is executed to
transfer an odd number of bytes across a wide bus then
the byte count at the end of the BMOV will be greater
than the number of bytes sent by one. This will also
happen in an odd byte count wide receive case. Also, in
the case of a wide send in which there is a chain byte
from a previous transfer, the count will not reflect the
chain byte sent across the bus during that BMOV. The
reason for this is due to the fact that to determine the
correct address to start fetching data from after a phase
mismatch this byte cannot be counted for this BMOV as
it was actually part of the byte count for the previous
BMOV.
Register: 0xDB
Reserved
Registers: 0xDC–0xDF
Cumulative SCSI Byte Count (CSBC)
Read/Write
CSBC
Cumulative SCSI Byte Count
[31:0]
This loadable register contains a cumulative count of the
actual number of bytes that have been transferred across
23
0
SBC
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
31
0
CSBC
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
*
Содержание LSI53C896
Страница 6: ...vi Preface...
Страница 16: ...xvi Contents...
Страница 88: ...2 62 Functional Description...
Страница 112: ...3 24 Signal Descriptions...
Страница 306: ...6 38 Specifications This page intentionally left blank...
Страница 310: ...6 42 Specifications This page intentionally left blank...
Страница 338: ...6 70 Specifications Figure 6 40 LSI53C896 329 BGA Bottom View...
Страница 340: ...6 72 Specifications...
Страница 346: ...A 6 Register Summary...
Страница 362: ...IX 12 Index...