AMC6821 datasheet(37/54 Pages) TI

37 / 54 page

www.ti.com

AMC6821

SBAS386C – MAY 2006 – REVISED JULY 2007

Configuration Register 2 (Address 0x01, Value After Power-On Reset = 0x3D)

BIT

NAME

R/W

DEFAULT

DESCRIPTION

Reset bits. RST = 1 resets the device. Self-clears after reset. Always read '0'. Power-on

RST

R/W

default = 0. Reset is immediate on rising edge of SCLK of data LSB with no

acknowledge.

LPSV enable bit. Power-on default = 0. When LPSVIE = 1, the LPSV interrupt is enabled

PSVIE

R/W

and an interrupt is generated when LPSV = 1. When LPSVIE = 0, LPSV is disabled and

LPSV = 1 does not cause an interrupt.

Remote temperature interrupt enable bit. When RTIE = 1, the remote temperature

interrupt is enabled and RTO = 1 causes an interrupt. When RTIE = 0, the remote

RTOIE

R/W

temperature interrupt is disabled and RTO = 1 does not generate an interrupt. Power-on

default = 1, except when a remote sensor failure is detected at power-on.

Local temperature interrupt enable bit. Power-on default = 1. When LTIE = 1, the local

LTOIE

R/W

temperature interrupt is enabled and LTO = 1 causes an interrupt. When LTIE = 0, the

local temperature interrupt is disabled and LTO = 1 does not generate an interrupt.

Remote sensor failure interrupt enable bit. Power-on default = 1. When RTFIE = 1, the

remote sensor failure interrupt is enabled and RTF = 1 causes an interrupt through the

RTFIE

R/W

SMBALERT pin. When RTFIE = 0, the remote sensor failure interrupt is disabled and

RTF = 1 does not generate an interrupt through the SMBALERT pin.

Setting this bit to '1' enables the TACH input. Clearing ('0') disables the TACH input and

TACH-EN

R/W

freezes the counter. Power-on default = 1. If TACH-EN is cleared, TACH-MODE must be

set ('1').

When the TACH-MODE bit is cleared ('0'), the PWM-Out pin is forced ON during RPM

measurement, and internal correction circuitry is enabled to correct the error caused by

this extra duty cycle. Making TACH-MODE = 0 for the fans that are switched ON/OFF

directly by the PWM requires PWM ON to provide TACH pulses. In the software RPM

mode, the PWM-Out is forced to 30% duty cycle if the calculated duty cycle is less than

30% when TACH-MODE = 0. In all other modes the PWM-Out is forced to 0% if the

TACH-MODE

R/W

calculated duty cycle is less than 7%. When the TACH mode is set ('1'), the internal

correction circuit is disabled and PWM-Out is not forced ON. Instead, the PWM-Out pin

is completely controlled by the value of the DCY register, just as in normal operation.

Setting the TACH-MODE bit ('1') when the fans can provide TACH pulses output

regardless the status of the PWM-Out pin. The TACH mode must be '1' for any fan

which is powered directly by dc power, such as a four-wire fan. Power-on default = 0.

(See the TACH-DATA Register section for details.)

Setting this bit to '1' enables the PWM-Out pin. Clearing ('0') disables the PWM-Out pin

PWM-EN

R/W

(H-Z). Power-on default = 1.

Configuration Register 3 (Address 0x3F, Value After Power-On Reset = 0x82)

BIT

NAME

R/W

DEFAULT

DESCRIPTION

Setting this bit to '1' enables the fan to run at full-speed when the THERM pin as

an output) is asserted low. This configuration allows the system to be run in

performance mode. Clearing this bit to '0' disables the fan from running at

THERM-FAN-EN

R/W

full-speed whenever the THERM pin (as an output) is asserted low. This

configuration allows the system to run in silent mode. Note that this bit has no

effect whenever THERM is pulled low as an input. The fan always runs at full

speed when the THERM pin is pulled low as an input. Power-on default = 1.

Reserved

Read-back '0'.

Reserved

Read-back '0'.

Reserved

Read-back '0'.

Part Revision Number

0, bit 3 (MSB) of 4-bit revision number.

Part Revision Number

0, bit 2 of revision number.

Part Revision Number

0, bit 1 of revision number.

Part Revision Number

0, bit 0 (LSB) of revision number.

Submit Documentation Feedback

Product Folder Link(s): AMC6821

AMC6821 데이터시트(PDF) 37 Page - Texas Instruments

AMC6821 데이터시트(HTML) 37 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

데이터시트 다운로드

링크 URL