ds1841nt-r Maxim Integrated Products, Inc., ds1841nt-r Datasheet - Page 10

• Manufacturer Part Number: ds1841nt-r
• Description: Ds1841 - New! - Temperature-controlled, Nv, I?c, Logarithmic Resistor
• Manufacturer: Maxim Integrated Products, Inc.

Register 00h: Initial Value Register (IVR)
Register 02h: Control Register 0 (CR0)
Temperature-Controlled, NV, I
Logarithmic Resistor
The DS1841’s internal memory consists of both volatile
and NV registers that are organized into eight byte
10
00h
02h
______________________________________________________________________________________
FACTORY DEFAULT (IVR)
MEMORY TYPE
MEMORY TYPE
Bit 7
If SEE bit = 0, an I
updates IVR in NV memory with this new value. If SEE bit = 1, an I
sets the wiper position (volatile) and the IVR value is not modified. During power-up, IVR’s value is used to set the wiper
position.
FACTORY DEFAULT
MEMORY TYPE
Bit 7
Bit 7
Bits 6 to 0
Control Register 0 determines how the wiper position values (volatile and NV versions) are set, as well as how writes to
Control Register 1 are stored.
The IVR is located at memory address 00h and is implemented as EEPROM shadowed SRAM. This register can be
visualized as an SRAM byte (the WR portion) in parallel with an EEPROM byte (the IVR portion). The operation of the
register is controlled by the Shadow EEPROM (SEE) bit in Control Register 0, address 02h, bit 7. When the SEE bit = 0
(default), data written to memory address 00h by I
SEE = 1, only the SRAM (WR) is written to the new value. The EEPROM byte (IVR) continues to store the last value
written to it when SEE was 0. Reading memory address 00h reads the value stored in WR. The SEE bit is volatile and its
power-up default state is 0.
SEE
SEE Controls IVR and WR functionality, as well as the memory type for Control Register 1.
0 = (Default) Issuing an I
WRITE to address 00h sets both the wiper’s position (volatile) and the IVR value (nonvolatile) to the
same value. Writes to Control Register 1 (03h) are stored in shadowed SRAM and EEPROM.
1 = Issuing an I
address 00h only sets the wiper’s position (volatile). The IVR value is not modified. Writes to Control
Register 1 (03h) are stored in shadowed SRAM only.
Reserved.
Reserved
2
Memory Description
C READ retrieves the IVR value and an I
00h
NV
Volatile
00h
Volatile
2
C READ of the value in address 00h retrieves the WR value. Issuing an I
Reserved
2
C READ of the value in address 00h retrieves the IVR value. Issuing an I
Reserved
2
C actually gets stored in both SRAM (WR) and EEPROM (IVR). When
IVR
2
C WRITE sets the wiper position in volatile memory and
rows. Three control registers as well as specialized
data registers are used to control the wiper and drive
the LUT.
Reserved
2
C READ retrieves the WR value and an I
2
C,
Reserved
Register Descriptions
Reserved
2
C WRITE to
2
C WRITE
Reserved
2
C
Bit 0
Bit 0