Table 1. pio/dq pin function, Suspend thresholds, Figure 9. charge suspend threshold format – Rainbow Electronics DS2756 User Manual

Page 11: Figure 10. discharge suspend threshold format

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Table 1. PIO/DQ Pin Function

REGISTER BIT SETTING

PIO/DQ PIN FUNCTION

PIE

IOS

IE

PIO

xx x x 0

PIO pin: GPIO

¾Output LOW

00 x 0 1

PIO pin: GPIO

¾Output High-Z, Input mode

00

0

1

1

PIO pin: Alarm Comparator Interrupt Output

00 1 1 0

DQ pin: Alarm Comparator Interrupt Output (low for t

IL

)

PIO pin: GPIO

¾Output LOW

00 1 1 1

DQ pin: Alarm Comparator Interrupt Output (low for t

IL

)

PIO pin: GPIO

¾Output High-Z, Input mode

01
10
11

x

x

1

PIO pin: Suspend Interrupt Output

x

¾Don’t care.

SUSPEND THRESHOLDS

The suspend thresholds set the current level to enter and exit Suspend mode. The threshold levels are
programmable with a magnitude range of 0 to 4mV, and are compared against the value in the Current register.
Values are programmed in two’s complement format with an implied sign bit in a virtual 9

th

bit position. The Charge

Suspend Threshold register is always a positive value. The Discharge Suspend Threshold register is always a
negative value.

The thresholds define an inclusive, continuous range of currents in which the DS2756 enters or re-enters Suspend
mode from Active mode. The Charge Suspend Threshold represents the minimum measured charge current which
will cause the DS2756 to transition modes. The Discharge Suspend Threshold represents the minimum discharge
current which will cause the DS2756 to transition modes.


The user values of the suspend thresholds are programmed into two bytes located within EEPROM block 0. These
memory locations serve as current threshold values only when either PIE bit is set, and can be used as general
purpose EEPROM if PIE = 00b. A copy command is required to save the byte values to EEPROM. See the
memory section for information on copying shadow RAM to EEPROM.

Figure 9. Charge Suspend Threshold Format

Address

35h

2

7

2

6

2

5

2

4

2

3

2

2

2

1

2

0

MSb

LSb

15.625

mV/Rsns

Figure 10. Discharge Suspend Threshold Format

Address

34h

2

7

2

6

2

5

2

4

2

3

2

2

2

1

2

0

MSb

LSb

15.625

mV/Rsns

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