71m6543h-igtr/f Maxim Integrated Products, Inc., 71m6543h-igtr/f Datasheet - Page 57

• Manufacturer Part Number: 71m6543h-igtr/f
• Description: Energy Meter Ic
• Manufacturer: Maxim Integrated Products, Inc.

load is never applied in BRN, LCD, and SLP modes.
VSENSE[7:0] and STEMP[10:0] from the 71M6xx3 remote sensors.
In BRN mode, TEMP_PWR = TEMP_BSEL use:
In MSN mode, a 100 µA de-passivation load can be applied to the selected battery (i.e., selected by the
TEMP_BSEL bit) by setting the BCURR (I/O RAM 0x2704[3]) bit. Battery impedance can be measured by
taking a battery measurement with and without BCURR. Regardless of the BCURR bit setting, the battery
2.5.8 71M6xx3 VCC Monitor
The 71M6xx3 monitors its VCC pin voltage. The voltage of the VCC pin can be obtained by the
71M6543F/H by issuing a read command to the 71M6xx3. The 71M6543F/H must request both the
VSENSE[7:0] and STEMP[10:0] values from the 71M6xx3. See the 71M6xxx Data Sheet for the equation to
calculate the 71M6xx3 VCC pin voltage from the VSENSE[7:0] and STEMP[10:0] values read from the
71M6xx3.
See
2.5.9 UART and Optical Interface
The 71M6543F/H provides two asynchronous interfaces, UART0 and UART1. Both can be used to
connect to AMR modules, user interfaces, etc., and also support a mechanism for programming the on-chip
flash memory.
Referring to
designed to directly drive an external LED for transmitting data on an optical link. The pin OPT_RX has
the same threshold as the RX pin, but can also be used to sense the input from an external photo detector
used as the receiver for the optical link. OPT_TX and OPT_RX are connected to a dedicated UART port
(UART1).
The OPT_TX and OPT_RX pins can be inverted with configuration bits OPT_TXINV (I/O RAM 0x2456[0])
and OPT_RXINV (I/O RAM 0x2457[1]), respectively. Additionally, the OPT_TX output may be modulated at
38 kHz. Modulation is available in MSN and BRN modes (see
0x2456[1]) enables modulation. The duty cycle is controlled by OPT_FDC[1:0] (I/O RAM 0x2457[5:4]) ,
which can select 50%, 25%, 12.5%, and 6.25% duty cycle. A 6.25% duty cycle means that OPT_TX is
low for 6.25% of the period.
When not needed for UART1, OPT_TX can alternatively be configured as SEGDIO51. Configuration is
via the OPT_TXE[1:0] (I/O RAM 0x2456[3:2]) field and LCD_MAP[51] (I/O RAM 0x2405[0]). The
OPT_TXE[1:0] field allows the MPU to select VPULSE, WPULSE, SEGDIO51 or the output of the pulse
modulator to be sourced onto the OPT_TX pin. Likewise, the OPT_RX pin can alternately be configured
as SEGDIO55, and its control is OPT_RXDIS (I/O RAM 0x2457[2]) and LCD_MAP[55] (I/O RAM 0x2405[4]).
v1.0
from
OPT_TX UART
A
B
2.2.8.3 Control of the 71M6xx3 Isolated Sensor
Figure
VBAT
OPT_TXMOD = 0
14, UART1 includes an interface to implement an IR/optical port. The pin OPT_TX is
OPT_TXINV
(
orVBAT
© 2008–2011 Teridian Semiconductor Corporation
_
RTC
OPT_TXMOD
)
=
OPT_FDC
. 3
Figure 14: Optical Interface
291
V
+
A
(
BSENSE
EN
MOD
on page
2
DUTY
−
VARPULSE
142
B
WPULSE
A
22
)
⋅
DIO2
. 0
Table
for information on how to read
B
0255
OPT_FDC = 2 (25%)
OPT_TXMOD = 1,
OPT_TXE[1:0]
V
62). The OPT_TXMOD bit (I/O RAM
0
+
3
2
1
STEMP
1/38kHz
Internal
⋅
71M6543F/H Data Sheet
. 0
000328
OPT_TX
V
V3P3
57