xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxx x x x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xx xx

xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxx x x

xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxx

xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxx

[1]

Only the 4 LSBs are shown.

[2]

x0x0 in binary = 0, 2, 8 or A in hexadecimal

x0x1 in binary = 1, 3, 9 or B in hexadecimal

x1x0 in binary = 4, 6, C or E in hexadecimal

x1x1 in binary = 5, 7, D or F in hexadecimal

[3]

x can be either ‘0’ or ‘1’ since those bits are read-only bits.

Table 12.

Bus control sequence

Read Control Register performed by the master

Write Control Register performed by the master

Byte

read[1]

Status

NBUSON BUSON

NMYBUS

MYBUS

Byte

written[1][2]

Action performed

to take mastership

NBUSON[3] BUSON NMYBUS[3]

MYBUS

Hex

Hex

0

bus off

has control

0

0

0

0

4

bus on

x

1

x

0

1

bus off

no control

0

0

0

1

4

bus on, take control

x

1

x

0

2

bus off

no control

0

0

1

0

5

bus on, take control

x

1

x

1

3

bus off

has control

0

0

1

1

5

bus on

x

1

x

1

4

bus on

has control

0

1

0

0

-

no change

no write required

5

bus on

no control

0

1

0

1

4

take control

x

1

x

0

6

bus on

no control

0

1

1

0

5

take control

x

1

x

1

7

bus on

has control

0

1

1

1

-

no change

no write required

8

bus on

has control

1

0

0

0

-

no change

no write required

9

bus on

no control

1

0

0

1

0

take control

x

0

x

0

A

bus on

no control

1

0

1

0

1

take control

x

0

x

1

B

bus on

has control

1

0

1

1

-

no change

no write required

C

bus off

has control

1

1

0

0

0

bus on

x

0

x

0

D

bus off

no control

1

1

0

1

0

bus on, take control

x

0

x

0

E

bus off

no control

1

1

1

0

1

bus on, take control

x

0

x

1

F

bus off

has control

1

1

1

1

1

bus on

x

0

x

1