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Table 5.4 – LSI 53C810A User Manual

Page 88

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5-14

Operating Registers

R

Reserved

4

MO[3:0]

Max SCSI Synchronous Offset

[3:0]

These bits describe the maximum SCSI synchronous
offset used by the LSI53C810A when transferring
synchronous SCSI data in either the initiator or target
mode.

Table 5.5

describes the possible combinations and

their relationship to the synchronous data offset used by

40

2

4

5

200

5

200

37.50

1.5

4

6.25

160

6.25

160

33.33

1.5

4

5.55

180

5.55

180

25

1

4

6.25

160

6.25

160

20

1

4

5

200

5

200

16.67

1

4

4.17

240

4.17

240

Table 5.3

Examples of Synchronous Transfer Periods and Rates
for SCSI-1 (Cont.)

SCLK
(MHz)

SCF

÷

SCNTL3

Bits [6:4]

XFERP
SXFER

Bits [7:5]

Synch.

Send Rate

(Mbytes/s)

Synch.

Send

Period (ns)

Synch.

Receive

Rate

(Mbytes/s)

Synch.

Receive

Period (ns)

Table 5.4

Examples of Synchronous Transfer Periods and
Rates for Fast SCSI

SCLK
(MHz)

SCF

÷

SCNTL3

Bits [6:4]

XFERP
SXFER

Bits

[7:5]

Synch.

Send Rate

(Mbytes/s)

Synch.

Send

Period

(ns)

Synch.

Receive

Rate

(Mbytes)

Synch.

Receive

Period (ns)

66.67

1.5

4

11.11

90

11.11

90

66.67

1

5

8.88

112.5

11.11

90

50

1

4

12.5

80

12.5

80

50

1

5

10

100

12.5

80

40

1

4

10

100

10.0

100

37.50

1

4

9.375

106.67

9.35

106.67

33.33

1

4

8.33

120

8.33

120

25

1

4

6.25

160

6.25

160

20

1

4

5

200

5

200

16.67

1

4

4.17

240

4.17

240