71M6541D Datasheet, PDF (79/166 Pages) Maxim Integrated Products – 0.1% Accuracy Over 2000:1 Current Range Energy Meter ICs

71M6541D/F/G and 71M6542F/G Data Sheet
The TMUXOUT and TMUX2OUT pins may be used for diagnostics purposes during the product
development cycle or in the production test. The RTC 1-second output may be used to calibrate the
crystal oscillator. The RTC 4-second output provides higher precision for RTC calibration. RTCLK may
also be used to calibrate the RTC.
Table 65: TMUX[5:0] Selections
TMUX[5:0] Signal Name
Description
1
RTCLK
32.768 kHz clock waveform
9
WD_RST
Indicates when the MPU has reset the watchdog timer. Can be
monitored to determine spare time in the watchdog timer.
A
CKMPU
MPU clock – see Table 9
D
V3AOK bit
Indicates that the V3P3A pin voltage is ≥ 3.0 V. The V3P3A and
V3P3SYS pins are expected to be tied together at the PCB level.
The 71M654x monitors the V3P3A pin voltage only.
E
V3OK bit
Indicates that the V3P3A pin voltage is ≥ 2.8 V. The V3P3A and
V3P3SYS pins are expected to be tied together at the PCB level.
The 71M654x monitors the V3P3A pin voltage only.
1B
MUX_SYNC
Internal multiplexer frame SYNC signal. See Figure 6 and Figure
7.
1C
CE_BUSY interrupt
See 2.3.3 on page 25 and Figure 16 on page 47
1D
CE_XFER interrupt
1F
RTM output from CE
See 2.3.5 on page 25
Note:
All TMUX[5:0] values which are not shown are reserved.
Table 66: TMUX2[4:0] Selections
TMUX2[4:0] Signal Name
Description
0
WD_OVF
Indicates when the watchdog timer has expired (overflowed).
1
PULSE_1S
One second pulse with 25% Duty Cycle. This signal can be used
to measure the deviation of the RTC from an ideal 1 second
interval. Multiple cycles should be averaged together to filter out
jitter.
2
PULSE_4S
Four second pulse with 25% Duty Cycle. This signal can be used
to measure the deviation of the RTC from an ideal 4 second
interval. Multiple cycles should be averaged together to filter out
jitter. The 4 second pulse provides a more precise measurement
than the 1 second pulse.
3
RTCLK
32.768 kHz clock waveform
8
SPARE[1] bit – I/O RAM Copies the value of the bit stored in 0x2704[1]. For general
0x2704[1]
purpose use.
9
SPARE[2] bit – I/O RAM Copies the value of the bit stored in 0x2704[2]. For general
0x2704[2]
purpose use.
A
WAKE
Indicates when a WAKE event has occurred.
B
MUX_SYNC
Internal multiplexer frame SYNC signal. See Figure 6 and Figure
7.
C
MCK
See 2.5.3 on page 50
E
GNDD
Digital GND. Use this signal to make the TMUX2OUT pin static.
12
INT0 – DIG I/O
13
INT1 – DIG I/O
14
INT2 – CE_PULSE
15
INT3 – CE_BUSY
Interrupt 0. See 2.4.8 on page 40. Also see Figure 16 on page 47.
16
INT4 - VSTAT
17
INT5 – EEPROM/SPI
18
INT6 – XFER, RTC
1F
RTM_CK (flash)
See 2.3.5 on page 25.
Note:
All TMUX2[4:0] values which are not shown are reserved.