Rainbow Electronics DS2745 - Manual (Page 11)

DS2745 Low-Cost I 2 C Battery Monitor
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Table 5. MEMORY MAP
ADDRESS (HEX) DESCRIPTION READ/WRITE POR DEFAULT
00 Reserved —
01 Status/Config Register R/W 11000000b
02 to 08 Reserved —
09 to 0D Reserved —
0A Temperature Register MSB R
0B Temperature Register LSB R
0C Voltage Register MSB R
0D Voltage Register LSB R
0E Current Register MSB R
0F Current Register LSB R
10 Accumulated Current Register MSB R/W No Change
11 Accumulated Current Register LSB R/W No Change
12 to 61 Reserved —
61 Offset Bias Register R/W 00h
62 Accumulation Bias Register R/W 00h
63 to FF Reserved —
STATUS/CONFIG REGISTER
The Status/Config register is read/write with individual bits designated as read only. Bit values indicate status as
well as program or select device functionality.
Figure 10. STATUS/CONFIG REGISTER FORMAT
ADDRESS 01
BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
X PORF SMOD NBEN PIO A2 A1 A0
X — Reserved.
PORF — The Power-On-Reset Flag is set to indicate initial power-up. PORF is not cleared internally. The user
must write this flag value to a 0 in order to use it to indicate subsequent power-up events. If PORF indicates a
power-on-reset, the ACR could be misaligned with the actual battery state of charge. The system can request a
charge to full in order to synchronize the ACR with the battery charge state. PORF is read/write-to-zero.
SMOD — SLEEP Mode Enable. A value of 1 allows the DS2745 to enter sleep mode when both SDA and SCL
pins is low for 2s. A value of 0 disables the transition to sleep mode. The power-up default of SMOD = 0.
NBEN — Negative Blanking Enable. A value of 1 enables blanking of negative current values up to 25
mV. A value
of 0 disables blanking of negative currents. The power-up default of NBEN = 0.
PIO — Programmable Input/Output. PIO provides both control of the PIO open-drain output driver and readback of
the PIO pin logic level. Writing a 0 to PIO drives PIO pin low. Writing a 1 deactivates the PIO output and allows
readback of an external signal. Reading PIO returns the logic state on the pin. PIO is RESET on POR.
A2:A0 — I
2 C Slave Address bits. A2:A0 set the lower 3 bits of the I 2 C slave address. When modified from the
power-up default slave address of 1001000b, accessing the DS2745 requires the modified slave address following
a start or repeated start.