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Table 5.3 – LSI 53C810A User Manual

Page 87

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5-13

Use the following formula to calculate the synchronous
send and receive rates.

Table 5.3

and

Table 5.4

show

examples of possible bit combinations.

Synchronous Send Rate = (SCLK/SCF)/XFERP
Synchronous Receive Rate = (SCLK/SCF) /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

SCLK

SCSI clock

SCF

Synchronous Clock Conversion Factor,
SCNTL3 register, bits [6:4]

XFERP

Transfer period, SXFER register, bits [7:5]

Table 5.3

Examples of Synchronous Transfer Periods and Rates
for SCSI-1

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)

66.67

3

4

5.55

180

5.55

180

66.67

3

5

4.44

225

5.55

180

50

2

4

6.25

160

6.25

160

50

2

5

5

200

6.25

160