71M6521DE/71M6521FE
Energy Meter IC
DATASHEET
JANUARY 2008
Total Number of LCD
Segment Pins In-
cluding SEG0-SEG18
Total Number of DIO
DIO Pins in Addition
Pins Including DIO1,
to DIO1-DIO2
SEG in Addition
to SEG0-SEG18
LCD_NUM
DIO2
0
1
-
-
19
19
19
19
19
20
21
22
23
23
23
24
25
26
27
28
29
30
31
4-11, 14-17
4-11, 14-17
4-11, 14-17
4-11, 14-17
4-11, 14-17
4-11, 14-16
4-11, 14-15
4-11, 14
4-11
14
14
14
14
14
13
12
11
10
10
10
9
2
-
3
-
4
-
5
37
6
36-37
7
35-37
8
34-37
9
34-37
4-11
10
11
12
13
14
15
16
17
18
34-37
4-11
31, 34-37
30-31, 34-37
29-31, 34-37
28-31, 34-37
27-31, 34-37
26-31, 34-37
25-31, 34-37
24-31, 34-37
4-10
4-9
8
4-8
7
4-7
6
4-6
5
4-5
4
4
3
None
2
Note: LCD segment numbers are given without CKTEST/SEG19, E_RXTX/SEG38, E_TCLK/SEG33, and E_RST/SEG32.
Table 63: LCD and DIO Pin Assignment by LCD_NUM for the LQFP-64 Package
Connecting I2C EEPROMs
I2C EEPROMs or other I2C compatible devices should be connected to the DIO pins DIO4 and DIO5, as shown in Figure 33.
Pull-up resistors of roughly 10kΩ to V3P3D (to ensure operation in BROWNOUT mode) should be used for both SCL and SDA
signals. The DIO_EEX register in I/O RAM must be set to 01 in order to convert the DIO pins DIO4 and DIO5 to I2C pins SCL
and SDA
V3P3D
10kΩ
10kΩ
EEPROM
71M6521
DIO4
DIO5
SCL
SDA
.
Figure 33: I2C EEPROM Connection
v1.0
© 2005-2008 TERIDIAN Semiconductor Corporation
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