Rainbow Electronics LM63 - Manual (Page 19)

2.0 LM63 Registers
(Continued)
Configuration Register
ADDRESS
Hex
Read/
Write
Bits
POR
Value
Name Description
03 (09)
HEX
CONFIGURATION REGISTER
03 (09) R/W
7 0
ALERT
Mask
When this bit is a 0, ALERT interrupts are enabled.
When this bit is set to a 1, ALERT interrupts are masked, and the
ALERT pin is always in a high impedance (open) state.
6 0 STANDBY
When this bit is a 0, the LM63 is in operational mode, converting,
comparing, and updating the PWM output continuously.
When this bit is a 1, the LM63 enters a low power standby mode.
In STANDBY, continuous conversions are stopped, but a
conversion/comparison cycle may be initiated by writing any value to
register 0x0F. Operation of the PWM output in STANDBY depends on
the setting of bit 5 in this register.
5 0
PWM Disable
in STANDBY
When this bit is a 0, the LM63’s PWM output continues to output the
current fan control signal while in STANDBY.
When this bit is a 1, the PWM output is disabled (as defined by the
PWM polarity bit) while in STANDBY.
4:3 00 These bits are unused and always set to 0.
2 0
ALERT/Tach
Select
When this bit is a 0, the ALERT/Tach pin is an open drain ALERT
output.
When this bit is a 1, the ALERT/Tach pin is a high impedance
Tachometer input.
Note that if this bit is set, the function of the ALERT/Tach pin must be
Tach input, so an external ALERT condition will not occur.
1 0
T_CRIT Limit
Override
The T_CRIT limit for the remote diode is nominally 85˚C. This value can
be changed once after power-up by first setting this bit to a 1, then
programming a new T_CRIT value into the Remote Diode T_CRIT Limit
(register 0x19). The T_CRIT value can not be changed again except by
cycling power to the LM63.
0 0
RDTS Fault
Queue
0: an ALERT will be generated if any Remote Diode conversion result is
above the Remote High Set Point or below the Remote Low
Setpoint.
1: an ALERT will be generated only if three consecutive Remote Diode
conversions are above the Remote High Set Point or below the
Remote Low Setpoint.
LM63
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