Rainbow Electronics AT73C502 User Manual

Page 14

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AT73C500

14

The six data packages arrive as follows:

Figure 9. Data transfer to processor in six packages

In normal mode, the Sync LS byte indicates the number of
data package which will follow (value 0...5). There are also
two special situations indicated by this byte. Value six of
Sync LS byte means that the processor is expected to sup-
ply calibration data to AT73C500. Value seven is written by

AT73C500 in case power interruption is detected and bill-
ing information needs to be transferred to microprocessor.
In this case the processor knows that both packages 3 and
4 will follow one after each other as shown in Figure 10.

Table 5. Package 4

Byte

Data

Order

Meaning

1

Sync LS

Single byte

Synchronization

2

Sync MS

Single byte

Synchronization

3

Mode

Single byte

Mode information

4

Status

Single byte

Status information

5

REG15

(LS+2) byte

Reactive energy,
capacitive load

6

REG15

MS byte

Reactive energy,
capacitive load

7

REG15

LS byte

Reactive energy,
capacitive load

8

REG15

(LS+1) byte

Reactive energy,
capacitive load

9

REG16

(LS+2) byte

Counter

10

REG16

MS byte

Counter

11

REG16

LS byte

Counter

12

REG16

(LS+1) byte

Counter

13

REG17

LS byte

Frequency

14

REG17

MS byte

Frequency

15

REG18

LS byte

Reserved

16

REG18

MS byte

Reserved

Table 6. Package 5

Byte

Data

Order

Meaning

1

Sync LS

Single byte

Synchronization

2

Sync MS

Single byte

Synchronization

3

Mode

Single byte

Mode information

4

Status

Single byte

Status information

5

REG19

LS byte

Voltage, phase 1

6

REG19

MS byte

Voltage, phase 1

7

REG20

LS byte

Voltage, phase 2

8

REG20

MS byte

Voltage, phase 2

9

REG21

LS byte

Voltage, phase 3

10

REG21

MS byte

Voltage, phase 3

11

REG22

LS byte

Current, phase 1

12

REG22

MS byte

Current, phase 1

13

REG23

LS byte

Current, phase 2

14

REG23

MS byte

Current, phase 2

15

REG24

LS byte

Current, phase 3

16

REG24

MS byte

Current, phase 3

1

2

3

4

5

6

7

8

9

10

1

2

3

4

5

200ms = 655360 clocks @ 3.2768 MHz

20 ms

Pack

0

Pack

1

Pack

2

Pack

3

Pack

4

Pack

5

Pack

0

Pack

1

Pack

2

Pack

3

DATRDY

LINE PERIOD

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