SCSI Registers
4-33
The synchronous transfer period the LSI53C896 should
use when transferring SCSI data is determined in the
following example:
The LSI53C896 is connected to a hard disk which can
transfer data at 10 Mbytes/s synchronously. The
LSI53C896 SCSI function’s SCLK is running at 40 MHz.
The synchronous transfer period (SXFERP) is found as
follows:
SXFERP = Period/SSCP + ExtCC
Period = 1
÷
Frequency = 1
÷
10 Mbytes/s = 100 ns
SSCP = 1
÷
SSCF = 1
÷
40 MHz = 25 ns
(This SCSI synchronous core clock is determined in
SCNTL3 bits [6:4], ExtCC = 1 if SCNTL1 bit 7 is asserted
and the LSI53C896 is sending data. ExtCC = 0 if the
LSI53C896 is receiving data.)
SXFERP = 100
÷
25 = 4
Where
TP2
TP1
TP0
XFERP
0
0
0
4
0
0
1
5
0
1
0
6
0
1
1
7
1
0
0
8
1
0
1
9
1
1
0
10
1
1
1
11
SXFERP
Synchronous transfer period
SSCP
SCSI synchronous core period
SSCF
SCSI synchronous core frequency
ExtCC
Extra clock cycle of data setup
*
Summary of Contents for LSI53C896
Page 6: ...vi Preface...
Page 16: ...xvi Contents...
Page 88: ...2 62 Functional Description...
Page 112: ...3 24 Signal Descriptions...
Page 306: ...6 38 Specifications This page intentionally left blank...
Page 310: ...6 42 Specifications This page intentionally left blank...
Page 338: ...6 70 Specifications Figure 6 40 LSI53C896 329 BGA Bottom View...
Page 340: ...6 72 Specifications...
Page 346: ...A 6 Register Summary...
Page 362: ...IX 12 Index...