EMC2300-AZC SMSC, EMC2300-AZC Datasheet - Page 20

• Manufacturer Part Number: EMC2300-AZC
• Description: Industrial Temperature Sensors Auto Fan Contrllr Up to 4 Fans
• Manufacturer: SMSC

Specifications of EMC2300-AZC

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Chapter 6 Hardware Monitoring
Revision 0.32 (06-23-08)
6.1
6.2
6.2.1
6.2.2
6.3
Input Monitoring
Resetting the EMC2300
Monitoring Modes
The following sub-sections describe the
The
Ready/Lock/Start Register (0x40). Measured values from the analog inputs and temperature sensors
are stored in Reading Registers. The values in the reading registers can be accessed via the SMBus
interface. These values are compared to the programmed limits in the Limit Register. The out-of-limit
and diode fault conditions are stored in the Interrupt Status Registers.
Power-On Reset
All the registers in the Hardware Monitor Block, except the reading registers, reset to a default value
when power is applied to the block. The default state of the register is shown in the table in the
Register Summary subsection. The default state of Reading Registers are not shown because these
registers have indeterminate power on values.
Note: Usually the first action after power up is to write limits into the Limit Registers.
Soft Reset (Initialization)
Setting bit 7 of the CONF register performs a soft reset. This bit is self-clearing. Soft Reset performs
reset on all the registers except the Reading Registers.
The Hardware Monitor Block supports two Monitoring modes: Continuous Mode and Cycle Mode.
These modes are selected using bit 1 of the Special Function Register (7Ch). The following
subsections contain a description of these monitoring modes.
The hardware monitor conversion clock is 45KHz ± 10%. Temperature conversions take 96 clocks,
each (2.133ms nom.); voltage conversions take 68 clocks, each (1.511ms nom). The time to complete
a conversion cycle depends upon the number of inputs in the conversion sequence to be measured
(see
which is selected using the AVG[2:0] bits in the Special Function register (see
Function Register on page
For each mode, there are four options for the number of measurements that are averaged for each
temperature and voltage reading. These options are selected using bits[7:5] of the Special Function
register (7Ch). These bits are defined as follows:
Bits [7:5]
The AVG[2:0] bits determine the amount of averaging for each of the measurements that are performed
by the hardware monitor before the reading registers are updated
priority encoded where the most significant bit has highest priority. For example, when the AVG2 bit is
asserted, 32 averages will be performed for each measurement before the reading registers are
updated regardless of the state of the AVG[1:0] bits.
EMC2300
Table 6.3, “ADC Conversion Sequence,” on page
AVG[2:0]
device’s monitoring function is started by writing a ‘1’ to the START bit in the
67).
DATASHEET
EMC2300
20
Fan Control Device with High Frequency PWM and Temperature Monitors
Hardware Monitoring features.
22) and the amount of averaging per input,
(Table
6.1). The AVG[2:0] bits are
Register 7Ch: Special
SMSC EMC2300
Datasheet