DS2784 Maxim Integrated Products, DS2784 Datasheet - Page 24

• Manufacturer Part Number: DS2784
• Description: 1-Cell Stand-Alone Fuel Gauge IC
• Manufacturer: Maxim Integrated Products

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Calculation of Results
SPECIAL FEATURE REGISTER FORMAT
All register bits are read and write accessible, with default values specified in each bit definition.
PIOB—PIO Pin Sense and Control Bit. Writing a 0 to the PIOB bit activates the PIO pin open-drain output driver,
forcing the PIO pin low. Writing a 1 to PIOB disables the output driver, allowing the PIO pin to be pulled high or
used as an input. Reading PIOB returns the logic level forced on the PIO pin. Note that if the PIO pin is left floating
with PIOB set, a weak pulldown current source pulls the PIO pin to V
also set in Sleep mode to ensure the PIO pin is high-impedance in sleep mode.
Note: Do not write PIOB to 0 if PSPIO is enabled.
X—Reserved Bits.
EEPROM REGISTER
The EEPROM register provides access control of the EEPROM blocks. EEPROM blocks can be locked to prevent
alteration of data within the block. Locking a block disables write access to the block. Once a block is locked, it
cannot be unlocked. Read access to EEPROM blocks is unaffected by the lock/unlock status.
EEPROM REGISTER FORMAT
EEC—EEPROM Copy Flag. A 1 in this read-only bit indicates that a Copy Data Function command is in progress.
While this bit is high, writes to EEPROM addresses are ignored. A 0 value in this bit indicates that data can be
written to unlocked EEPROM.
LOCK—EEPROM Lock Enable. When the lock bit is 0, the Lock Function command is ignored. Writing a 1 to this
bit enables the Lock Function command. After setting the lock bit the lock function command must be issued as the
next command, or else the lock bit is reset to 0. After the lock operation is completed, the lock bit is reset to 0. The
lock bit is a volatile R/W bit, initialized to 0 upon POR.
RAAC [mAh] = (ACR[mVh] - AE(T) * FULL40[mVh]) * RSNSP [mhos]
Note: RSNSP = 1/RSNS
RSAC [mAh] = (ACR[mVh] - SE(T) * FULL40[mVh]) * RSNSP [mhos]
Note: RSNSP = 1/RSNS
RARC [%] = 100% * (ACR[mVh] - AE(T) * FULL40[mVh]) /
RSRC [%] = 100%* (ACR[mVh] - SE(T) * FULL40[mVh]) /
BIT 7
BIT 7
EEC
X
DS2784: 1-Cell Stand-Alone Fuel Gauge IC with Li+ Protector and SHA-1 Authentication
LOCK
BIT 6
BIT 6
X
BIT 5
BIT 5
X
X
{(AS * FULL(T) - AE(T)) * FULL40[mVh]}
{(AS * FULL(T) - SE(T)) * FULL40[mVh]}
BIT 4
BIT 4
ADDRESS 15H
ADDRESS 1Fh
X
X
24 of 37
BIT 3
BIT 3
X
X
SS
BIT 2
BIT 2
. PIOB is set to a 1 on power-up. PIOB is
X
X
BIT 1
BIT 1
BL1
X
BIT 0
PIOB
BIT 0
BL0