Datasheet

www.ti.com

AMC6821

SBAS386C – MAY 2006 – REVISED JULY 2007

TACH Low Limit Register

TACH-Low-Limit-LByte Register (Address 0x10, Power-On Default = 0xFF)

Bit 7 (MSB) Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 (LSB)

TACH-Low-Limit7 TACH-Low-Limit6 TACH-Low-Limit5 TACH-Low-Limit4 TACH-Low-Limit3 TACH-Low-Limit2 TACH-Low-Limit1 TACH-Low-Limit0

TACH-Low-Limit-HByte Register (Address 0x11, Power-On Default = 0xFF)

Bit 7 (MSB) Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 (LSB)

TACH-Low- TACH-Low- TACH-Low- TACH-Low- TACH-Low- TACH-Low- TACH-Low- TACH-Low-

Limit15 Limit14 Limit13 Limit12 Limit11 Limit10 Limit9 Limit8

Bits [TACH-Low-Limit15:TACH-Low-Limit0] are the value that corresponds to the predetermined minimum

allowable fan speed (RPM). If the value of the TACH data register is greater than this bound, the fan speed is

below the minimum allowed RPM.

TACH High Limit Register

TACH-High-Limit-LByte Register (Address 0x12, Power-On Default = 0x00)

Bit 7 (MSB) Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 (LSB)

TACH-High-Limit7 TACH-High-Limit6 TACH-High-Limit5 TACH-High-Limit4 TACH-High-Limit3 TACH-High-Limit2 TACH-High-Limit1 TACH-High-Limit0

TACH-High-Limit-HByte Register (Address 0x13, Power-On Default = 0x00)

Bit 7 (MSB) Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 (LSB)

TACH-High- TACH-High- TACH-High- TACH-High- TACH-High- TACH-High- TACH-High-Limit9 TACH-High-Limit8

Limit15 Limit14 Limit13 Limit12 Limit11 Limit10

Bits [TACH-High-Limit15:TACH-High-Limit0] are the value that corresponds to the predetermined maximum

allowable fan speed (RPM). If the value of the TACH data register is smaller than this bound, the fan speed is

above the maximum allowed RPM.

Product Folder Link(s): AMC6821