SBAS475A June 2009 – January 2023 AMC6821-Q1
PRODUCTION DATA
All registers are 8-bit. Table 8-13 shows the memory map. Locations that are marked Reserved read back 0x0000 if they are read by the host. Writing to these locations has no effect.
ADDR | NAME | R/W | DEFAULT | BIT 7 | BIT 6 | BIT 5 | BIT 4 | BIT 3 | BIT 2 | BIT 1 | BIT 0 |
---|---|---|---|---|---|---|---|---|---|---|---|
IDENTIFICATION REGISTERS | |||||||||||
0x3D | Device ID Register | R | 0x21 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 1 |
Device identification number. Always read '0x21'. | |||||||||||
0x3E | Company ID Register | R | 0x49 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 1 |
Company identification number. | |||||||||||
CONFIGURATION REGISTERS | |||||||||||
0x00 | Configuration Register 1 | R/W | 0xD4 | THERMOVIE | FDRC1 | FDRC0 | FAN-Fault-EN | PWMINV | FANIE | INT-EN | START |
THERM INT Enable | Fan Control Mode | FAN-Fault Pin EN | PWM Invert | RPM Int EN | Global Int EN | Start Monitor | |||||
0x01 | Configuration Register 2 | R/W | 0x3D | RST | PSVIE | RTOIE | LTOIE | RTFIE | TACH-EN | TACH-MODE | PWM-EN |
Reset | LPSV Int EN | RT Int EN | LT Int EN | Remote Failure Int EN | TACH EN | TACH Mode | PWM-Out EN | ||||
0x3F | Configuration Register 3 | R/W | 0x82 | THERM-FAN-EN | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
THERM-Fan Control | Part Revision Number | ||||||||||
0x04 | Configuration Register 4 | R/W | 0x08 | For Future Use | PSPR | TACH-FAST | OVREN | 1 | 0 | 0 | 0 |
Must be rewritten to '1'. | Pulse Number | TACH Reading Fast | OVR Pin EN | Reserved | |||||||
0x02 | Status Register 1 | R | 0x00 | LTL | LTH | RTF | R-THERM | RTL | RTH | FANS | RPM-ALARM |
LT Low | LT High | RT Failure | RT Over Therm | RT Low | RT High | Fan Slow | Fan Fast | ||||
0x03 | Status Register 2 | R | 0x00 | THERM-IN | L-THERM | LPSV | LTC | RTC | 0 | 0 | 0 |
Therm Input | LT Over Therm | LT Below Therm | LT Over Critical | RT Over Critical | Reserved | ||||||
TEMPERATURE MONITORING | |||||||||||
0x06 | Temp-DATA-LByte | R | 0x00 | LT2 | LT1 | LT0 | 0 | 0 | RT2 | RT1 | RT0 |
3 LSBs of Local Reading | Reserved | 3 LSBs of Remote Reading | |||||||||
0x0A | Local-Temp-DATA-HByte | R | 0x80 | LT10 (MSB) | LT9 | LT8 | LT7 | LT6 | LT5 | LT4 | LT3 |
The 8 MSBs of newest reading of local temperature sensor. Default = –128°C. | |||||||||||
0x0B | Remote-Temp-DATA-HByte | R | 0x80 | RT10 (MSB) | RT9 | RT8 | RT7 | RT6 | RT5 | RT4 | RT3 |
The 8 MSBs of newest reading of remote temperature sensor. Default = –128°C. | |||||||||||
0x14 | Local-High-Temp-Limit | R/W | 0x3C | LT-H10 | LT-H9 | LT-H8 | LT-H7 | LT-H6 | LT-H5 | LT-H4 | LT-H3 |
8 MSBs of upper-bound threshold of out-of-range detection of Local-Temp. 3 LSBs are '0'. Default = +60°C. | |||||||||||
0x15 | Local-Low-Temp-Limit | R/W | 0x00 | LT-L10 | LT-L9 | LT-L8 | LT-L7 | LT-L6 | LT-L5 | LT-L4 | LT-L3 |
8 MSBs of lower-bound threshold of the out-of-range detection of Local-Temp. 3 LSBs are '0'. Default = 0°C. | |||||||||||
0x16 | Local-THERM-Limit | R/W | 0x46 | LT-T10 | LT-T9 | LT-T8 | LT-T7 | LT-T6 | LT-T5 | LT-T4 | LT-T3 |
8 MSBs of local THERM temperature limit. 3 LSBs are '0'. When local temperature is equal to or above this limit, L-THERM is detected. Default = +70°C. | |||||||||||
0x18 | Remote-High-Temp-Limit | R/W | 0x50 | RT-H10 | RT-H9 | RT-H8 | RT-H7 | RT-H6 | RT-H5 | RT-H4 | RT-H3 |
The 8 MSBs of the upper-bound threshold of the out-of-range detection of Remote-Temp. 3 LSBs are '0'. Default = +80°C. | |||||||||||
0x19 | Remote-Low-Temp-Limit | R/W | 0x00 | RT-L10 | RT-L9 | RT-L8 | RT-L7 | RT-L6 | RT-L5 | RT-L4 | RT-L3 |
The 8 MSBs of the lower-bound threshold of the out-of-range detection of Remote-Temp. 3 LSBs are '0'. Default = 0°C. | |||||||||||
0x1A | Remote-THERM-Limit | R/W | 0x64 | RT-T10 | RT-T9 | RT-T8 | RT-T7 | RT-T6 | RT-T5 | RT-T4 | RT-T3 |
8 MSBs of Remote THERM temperature limit. 3 LSBs are '0'. When remote temperature is equal to or above this limit, R-THERM is detected. Default = +100°C. | |||||||||||
0x1B | Local-Critical-Temp | R/W | 0x50 | LT-C10 | LT-C9 | LT-C8 | LT-C7 | LT-C6 | LT-C5 | LT-C4 | LT-C3 |
The 8 MSBs of Local Critical temperature shutdown threshold. 3 LSBs are '0'. When the Local-Temp is equal to or above this limit, the LTC interrupt occurs and OVR goes low. Default = +80°C. | |||||||||||
TEMPERATURE MONITORING (continued) | |||||||||||
0x1C | PSV-Temp | R/W | 0x00 | 0 | 0 | PSV8 | PSV7 | PSV6 | PSV5 | PSV4 | PSV3 |
Passive Cooling Temperature threshold. 3 LSBs and two MSBs are '0'. For details, refer to the passive cooling temperature limit in the Temperature Out-of-Range Detection section. Default = 0°C. | |||||||||||
0x1D | Remote-Critical-Temp | R/W | 0x69 | RT-C10 | RT-C9 | RT-C8 | RT-C7 | RT-C6 | RT-C5 | RT-C4 | RT-C3 |
The 8 MSBs of Remote Critical temperature shutdown threshold. 3 LSBs are '0'. When the Remote-Temp is equal to or above this limit, an RCRT interrupt occurs and OVR goes low. Default = +105°C. | |||||||||||
PWM CONTROLLER | |||||||||||
0x20 | FAN-Characteristics | R/W | 0x1D | FSPD | 0 | PWM2 | PWM1 | PWM0 | STIME2 | STIME1 | STIME0 |
Spin Dis | PWM Frequency Setting | Spin-Up Time Setting | |||||||||
0x21 | DCY-Low-Temp | R/W | 0x55 | L-DCY7 | L-DCY6 | L-DCY5 | L-DCY4 | L-DCY3 | L-DCY2 | L-DCY1 | L-DCY0 |
The duty cycle of PWM when the temperature is equal to or below Low-Temp in Auto Temp-Fan Control mode. Default = 0x55, 33.2%. | |||||||||||
0x22 | DCY (Duty Cycle) | R/W | 0x55 | DCY7 (MSB) | DCY6 | DCY5 | DCY4 | DCY3 | DCY2 | DCY1 | DCY0 |
Actual Duty cycle of PWM output. The duty cycle changes immediately after new data are written into this register. 8-bit, 0.39%/bit, range 0%-100%. Default = 33%. In read operation, the returned data are the actual DCY value driving the PWM-Out pin with two exceptions. Refer to the DCY Register section. In write operation, the data written are the actual DCY value driving the PWM-Out pin in Software-DCY control mode. In all other control modes, the data are not used to drive the PWM. Instead, they are stored in a temporary register, and used to control the PWM immediately after the control mode is changed to software-DCY control. | |||||||||||
0x23 | DCY-RAMP | R/W | 0x52 | RAMPE | STEP1 | STEP0 | RATE2 | RATE1 | RATE0 | THRE1 | THRE0 |
Ramp Enable | DCY Adjustment Step in Auto Fan Control | DCY Update Rate in Auto Temp-Fan Control | Adjustment Threshold in Auto Temp-Fan Control | ||||||||
0x24 | Local Temp-Fan Control(1) | R/W | 0x41 | L-TEMP4 | L-TEMP3 | L-TEMP2 | L-TEMP1 | L-TEMP0 | L-SLP2 | L-SLP1 | L-SLP0 |
Low-Temp in Auto Local Temp-Fan control. | Slope in Auto Local Temp-Fan control. | ||||||||||
0x25 | Remote Temp-Fan Control | R/W | 0x61 | R-TEMP4 | R-TEMP3 | R-TEMP2 | R-TEMP1 | R-TEMP0 | R-SLP2 | R-SLP1 | R-SLP0 |
Low-Temp in Auto Remote Temp-Fan control. | Slope in Auto Remote Temp-Fan control. | ||||||||||
TACH (RPM) MEASUREMENT | |||||||||||
0x08 | TACH-DATA-LByte | R | 0x00 | TACH- DATA7 | TACH-DATA6 | TACH-DATA5 | TACH-DATA4 | TACH-DATA3 | TACH-DATA2 | TACH-DATA1 | TACH-DATA0 |
Low byte of TACH measurement. | |||||||||||
0x09 | TACH-DATA-HByte | R | 0x00 | TACH-DATA15 | TACH-DATA14 | TACH-DATA13 | TACH-DATA12 | TACH-DATA11 | TACH-DATA10 | TACH-DATA9 | TACH-DATA8 |
High byte of TACH measurement. | |||||||||||
0x10 | TACH-Low-Limit-LByte | R/W | 0xFF | TACH-Low-Limit7 | TACH-Low-Limit6 | TACH-Low-Limit5 | TACH-Low-Limit4 | TACH-Low-Limit3 | TACH-Low-Limit2 | TACH-Low-Limit1 | TACH-Low-Limit0 |
Low byte of TACH count limit corresponding to minimum allowed RPM. Since the TACH circuit counts between TACH pulses, a slow fan results in a larger measured value. When the measured value is larger than TACH-Low-Limit, the fan runs below the allowed minimum speed limit. | |||||||||||
0x11 | TACH-Low-Limit-HByte | R/W | 0xFF | TACH-Low-Limit15 | TACH-Low-Limit14 | TACH-Low-Limit13 | TACH-Low-Limit12 | TACH-Low-Limit11 | TACH-Low-Limit10 | TACH-Low-Limit9 | TACH-Low-Limit8 |
High byte of TACH Limit corresponding to minimum allowed RPM. | |||||||||||
0x12 | TACH-High-Limit-LByte | R/W | 0x00 | TACH-High-Limit7 | TACH-High-Limit6 | TACH-High-Limit5 | TACH-High-Limit4 | TACH-High-Limit3 | TACH-High-Limit2 | TACH-High-Limit1 | TACH-High-Limit0 |
Low byte of TACH count Limit corresponding to maximum allowed RPM. Since the TACH circuit counts between TACH pulses, a fast fan results in a small measured value. When the measurement is less than this limit, the fan runs above the allowed maximum speed limit. | |||||||||||
0x13 | TACH-High-Limit-HByte | R/W | 0x00 | TACH-High-Limit15 | TACH-High-Limit14 | TACH-High-Limit13 | TACH-High-Limit12 | TACH-High-Limit11 | TACH-High-Limit10 | TACH-High-Limit9 | TACH-High-Limit8 |
High byte of TACH limit corresponding to maximum allowed RPM. | |||||||||||
0x1E | TACH-SETTING-LByte | R/W | 0xFF | TACH-SETTING7 | TACH-SETTING6 | TACH-SETTING5 | TACH-SETTING4 | TACH-SETTING3 | TACH-SETTING2 | TACH-SETTING1 | TACH-SETTING0 |
Low byte of TACH value corresponding to the predetermined target fan speed. TACH-SETTING must be not greater than the value corresponding to the RPM for 30% duty cycle when the TACH-MODE bit is cleared ('0'). | |||||||||||
0x1F | TACH-SETTING-HByte | R/W | 0xFF | TACH-SETTING15 | TACH-SETTING14 | TACH-SETTING13 | TACH-SETTING12 | TACH-SETTING11 | TACH-SETTING10 | TACH-SETTING9 | TACH-SETTING8 |
High byte of TACH value corresponding to the predetermined fan speed. TACH-SETTING must be not greater than the value corresponding to the RPM for 30% duty cycle when the TACH-MODE bit is cleared ('0'). | |||||||||||
0x3A | Reserved | R | 0x00 | Always read '0'. | |||||||
0x3B | Reserved | R | 0x00 | Always read '0'. |