10

®

ADC574A

from the conversion followed by four logic zeros which

have been forced by the control logic. The left-justified

formats of the two 8-bit bytes are shown in Figure 8. The

toggled at any time with no damage to the converter; the

outputs which are tied together as illustrated in Figure 9

cannot be enabled at the same time.

In the majority of applications the read operation will be

attempted only after the conversion is complete and the

STATUS output has gone low. In those situations requiring

the earliest possible access to the data, the read may be

started as much as 1.15

µs (t

STATUS goes low. Refer to Figure 7 for these timing

relationships.

FIGURE 8. 12-Bit Data Format for 8-Bit Systems.

Processor

DB7

DB6

DB5

DB4

DB3

DB2

DB1

DB0

DB7

DB6

DB5

DB4

DB3

DB2

DB1

DB0

Converter

DB11

DB10

DB9

DB8

DB7

DB6

DB5

DB4

DB3

DB2

DB1

DB0

0

0

0

0

Word 1

Word 2

FIGURE 9. Connection to an 8-Bit Bus.

12/8

A

STATUS

DB11 (MSB)

DB0 (LSB)

Digital Common

O

ADC574A

28

27

26

25

24

23

22

21

20

19

18

17

16

15

2

4

Data

Bus

Address

Bus

A

O