71M6531F-IM/F Maxim Integrated Products, 71M6531F-IM/F Datasheet - Page 41

• Manufacturer Part Number: 71M6531F-IM/F
• Description: IC ENERGY METER 256KB 68-QFN
• Manufacturer: Maxim Integrated Products

Specifications of 71M6531F-IM/F

• Mounting Style: SMD/SMT
• Package / Case: QFN-68
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

inputs (no current limiting resistors are needed). The Digital I/O pins can be categorized as follows:
The pins DIO4/SEG24 through DIO46/SEG66 are configured by the LCD_BITMAP registers to be DIO or
segment pins. A one in LCD_BITMAP defines the pin as a LCD segment output, a zero makes the pin a
DIO pin. Pins configured as LCD pins are controlled with the LCD_SEGnn registers. Pins configured as
DIO can be defined independently as an input or output with the DIO_DIR bits (see
A 3-bit configuration word, I/O RAM field DIO_Rx[2:0] (0x2009[2:0] through 0x200E[6:4]), can be used for
certain pins (when configured as DIO) to individually assign an internal resource such as an interrupt or a
timer control (see
even if they are configured as outputs.
Table 39
FDS 6531/6532 005
1.5.7
The 71M6531D/F includes up to 22 pins of general-purpose digital I/O. These pins are compatible with 5 V
v1.3
• Dedicated DIO pins (1 pin): PB
• DIO/LCD segment pins (a total of 19 pins):
• DIO pins combined with other functions (2 pins): DIO2/OPT_TX, DIO1/OPT_RX
from
OPT_TX UART
A
B
Write operations to a disabled DIO are not ignored. Write operations are registered, but do not affect
the pin, or the result of a read operation on the pin, until it becomes a DIO output.
DIO2/OPT_TX will be an active TX output pin at power up (OPT_TXE[1:0] = 00).
Digital I/O – 71M6531D/F
o
o
o
o
to
Table 41
DIO4/SEG24 - DIO15/SEG35 (12 pins)
DIO17/SEG37 (1 pin)
DIO28/SEG48 – DIO29/SEG49 (2 pins)
DIO43/SEG63 - DIO46/SEG66 (4 pins)
Table 46
OPT_TXMOD = 0
lists the direction registers and configurability associated with each group of DIO pins.
OPT_TXINV
© 2005-2010 TERIDIAN Semiconductor Corporation
for DIO pins available for this option). This way, DIO pins can be tracked
OPT_TXMOD
OPT_FDC
Figure 9: Optical Interface
A
EN
MOD
2
DUTY
VARPULSE
B
WPULSE
A
DIO2
B
OPT_FDC = 2 (25%)
OPT_TXMOD = 1,
Data Sheet 71M6531D/F-71M6532D/F
OPT_TXE[1:0]
0
3
2
1
1/38kHz
Internal
Table
OPT_TX
45).
V3P3
41