Table 6: remote interface read commands, Table 7: i/o ram control bits for isolated sensor – Rainbow Electronics 71M6542G User Manual
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111
Reserved
Notes:
1. Only two codes of RCMD[4:2] (SFR 0xFC[4:2]) are relevant for normal
operation. These are RCMD[4:2] = 001 and 010. Codes 000 and 101
are invalid and will be ignored if used. The remaining codes are
reserved and must not be used.
2. For the RCMD[1:0] control field, codes 01, 10 and 11 are valid and 00
is invalid and must not be used.
shows the allowable combinations of values in RCMD[4:2] and TMUXRn[2:0], and the
corresponding data type and format sent back by the 71M6x01 isolated sensor and how the data is stored
in RMT_RD[15:8] and RMT_RD[7:0]. The MPU selects which of the three phases is read by asserting the
proper code in the RCMD[1:0] field, as shown in
Table 6: Remote Interface Read Commands
RCMD[4:2]
TMUXRn[2:0]
Read Operation
RMT_RD [15:8]
RMT_RD [7:0]
001
00X
TRIMT[7:0]
(trim fuse for all 71M6x01)
TRIMT[7]=RMT_RD[8]
TRIMT[6:0]=RMT_RD[7:1]
010
00X
STEMP[10:0]
(sensed 71M6x01 temperature)
STEMP[10:8]=RMT_RD[10:8]
(RMT_RD[15:
11] are sign extended)
STEMP[7:0]
010
01X
VSENSE[7:0]
(sensed 71M6x01 supply voltage)
All zeros
VSENSE[7:0]
010
10X
VERSION[7:0]
(chip version)
VERSION[7:0]
All zeros
Notes:
1. TRIMT[7:0] is the VREF trim value for all 71M6x01 devices. Note that the TRIMT[7:0] 8-bit value is formed
by RMT_RD[8] and RMT_RD[7:1]. See the 71M6xxx Data sheet for more information on TRIMT[7:0]
2. See the 71M6xxx Data Sheet for the equation to calculate temperature from the
STEMP[7:0]
value read from
the 71M6x01.
3. See the 71M6xxx Data Sheet for the equation to calculate temperature from the
VSENSE[7:0]
value read from
the 71M6x01.
With hardware and trim-related information on each connected 71M6x01 Isolated Sensor available to the
71M6541D/F, the MPU can implement temperature compensation of the energy measurement based on the
individual temperature characteristics of the 71M6x01 Isolated Sensor. See
shows all I/O RAM registers used for control of the external 71M6x01 Isolated Sensors. See the
71M6xxx Data Sheet for additional details.
Table 7: I/O RAM Control Bits for Isolated Sensor
Name
Address
RST
Default
WAKE
Default
R/W Description
RCMD[4:0]
SFR
FC[4:0]
0
0
R/W
When the MPU writes a non-zero value to RCMD,
the 71M654x issues a command to the cor-
responding isolated sensor selected with
RCMD[1:0]. When the command is complete, the
71M654x clears RCMD[4:2]. The command code
itself is in RCMD[4:2].
PERR_RD
PERR_WR
SFR FC[6]
SFR FC[5]
0
0
R/W
The 71M654x sets these bits to indicate that a
parity error on the isolated sensor has been de-
tected. Once set, the bits are remembered until
they are cleared by the MPU.
CHOPR[1:0]
2709[7:6]
00
00
R/W
The CHOP settings for the isolated sensors.
00 – Auto chop. Change every multiplexer frame.
01 – Positive
10 – Negative
11 – Same as 00