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8.0 Health Management (HM) (Continued)

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A “reset” operation on the bus can be initiated by either the HM or the LMxx Sensor devices generating a reset signal. After

VSB Power-Up reset, the HM holds the SensorPath bus low, thus resetting the bus. Then, the HM releases the reset from

the SensorPath bus. Following this, the HM is ready to respond to “attention requests” from an LMxx Sensor device.

When the HM performs a reset operation on the bus, the reset signal is followed by a sequence of 16 data bits (all 0), without

a preceding start bit. If the SensorPath bus remains in reset state (i.e., SWD is held low by an LMxx Sensor device) for more

than the maximum reset time allowed, the HM assumes that a major SensorPath bus failure occurred and proceeds accord-

ingly (see Section 8.2.10 on page 139).

When an LMxx Sensor device contains new data, it sends an attention request to the HM. The HM answers the attention

request by initiating a read transaction on the SensorPath bus.

If a SensorPath data or start bit collides with an attention request, the data or start bit is automatically resent. In addition, if

a parity or acknowledge error occurs on the first transaction attempt, two more successive attempts are made by the HM. If

the LMxx Sensor device detects an acknowledge error, it generates an attention request and sets BER bit in the Device

Status register. The HM checks BER bit in response to each attention request to determine the cause of the request.

The HM initiates read/write transactions on the SensorPath bus and supports data fields of up to 32 bits.

8.2.3

Temperature Monitoring

Temperature is monitored for three different temperature zones (or channels). The temperature data is updated and stored

as a 2’s complement, left-aligned, 8-bit data byte in the Temperature Reading Zone1-3 registers.

The following table shows the association of the LMxx temperature channels to the HM temperature channels for each pos-

sible LMxx devices setup:

When Temperature Zone3 is associated with an LM95010 device, the associated Temperature Reading Register represents

a value between -127

°C (81h) and +127°C (7Fh), with the LSBit representing a value of 1°C. For Temperature Zones 1 and

2, and for Temperature Zone3 when it is not associated with an LM95010 device, the Temperature Reading register depends

on the setting of the ZONEn_RANGE bit in the Monitor Control Register (see Section 8.5.54 on page 176).

If ZONEn_RANGE is 0, the LSBit of the Reading register represents a value of 1

°C (thus temperature values are between

-127

°C (81h) and +127°C (7Fh)). If ZONEn_RANGE bit is 1 the LSBit of the Reading register represents a value of 2°C (thus

temperature values are between -254

°C (81h) and +254°C (7Fh)); see also Figure 37 on page 158. A value of 80h always

represents a sensor error.

The temperature data can be gain- and offset-corrected with the values in the Temperature Zone ‘n’ Gain and Offset Cor-

rection registers (see Section 8.5.56 on page 178 to Section 8.5.58). The temperature gain correction in the HM can be used

to compensate the non-ideality of the thermal diodes (remote diode) connected to the LMxx Sensor devices (see the “Ap-

plication Hints” section in the respective LMxx Datasheet). The offset correction can be used to compensate the PCB trace

resistance between the remote diode and the LMxx Sensor device (see “Application Hints” in the respective LMxx

Datasheet).

The temperature data can be low-pass filtered by setting the TEMP_FILT bit in the Monitoring Control register (see

Section 8.5.54 on page 176). The rise time of the filter (0% to 95% of the incoming temperature change) is 673 ms.

The temperature data is compared with configurable low and high limits contained in the Temperature Low Limit Zone1-3

and Temperature High Limit Zone1-3 registers, respectively, and with the critical limit contained in the Temperature Critical

Limit Zone1-3 registers. The data format in the limit registers is the same as in the temperature data registers. Note that a

value of 80h must not be used as a limit value.

Whenever the temperature data exceeds a low or high limit, a ZONEn_ERR status bit is set in the Status Register 1 (see

Section 8.5.23 on page 164), and the ZONEn_STS bit in the HM Sensor Status Register 1 is set (see Section 8.4.8 on

page 147). Whenever the temperature data exceeds a critical limit, a CRITn_ERR status bit is set in the Status Register 3

(see Section 8.5.25 on page 166), and the CRITn_STS bit in the HM Sensor Status Register 3 is set (see Section 8.4.12 on

page 150).

Temperature data is considered to be in a “Good” state when the data does not exceed any limit. A “Fail” state is when the

temperature data exceeds a limit (high, low or critical).

Table 48. Temperature Channels per LMxx Device

LMxx Device Setup

Temperature Zones

Temperature Zone1

Temperature Zone2

Temperature Zone3

LM96011

LM96011 Remote

LM96011 Ambient

LM96011+LM95010

LM96011 Remote

LM96011 Ambient

LM95010 Ambient

LM96010

LM96010 First Remote

LM96010 Ambient

LM96010 Second Remote

LM96012

LM96012 First Remote

LM96012 Ambient

LM96012 Second Remote

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