Datasheet
Data Sheet ADT7470
Rev. E | Page 19 of 40
Masking Interrupt Sources
Interrupt Mask Register 1 and Interrupt Mask Register 2 are
located at Address 0x72 and Address 0x73. These allow indi-
vidual interrupt sources to be masked out to prevent unwanted
SMBALERT
interrupts. Masking an interrupt source prevents
only the
SMBALERT
output from being asserted; the appro-
priate status bit is still set as usual. This is useful if the system
polls the monitoring devices periodically to determine whether
or not out-of-limit conditions have subsided, without tying up
time-critical system resources.
Enabling the
SMBALERT
Interrupt Output
The
SMBALERT
interrupt output is a dedicated function pro-
vided on Pin 14 to signal out-of-limit conditions to a host or
system processor. Because this is a dedicated function, it is
important that limit registers be programmed before monitoring
is enabled to prevent spurious interrupts from occurring on the
SMBALERT
pin. Although the
SMBALERT
output cannot be
specifically disabled, interrupt sources can be masked to prevent
SMBALERT
assertions. Monitoring is enabled when Bit 0 (STRT)
of Configuration Register 1 (Register 0x40) is set to 1.
Table 14. Interrupt Mask Register 1 (Register 0x72)
Bit No. Mnemonic Description
7 Unused Unused.
6 R7T A 1 masks the
SMBALERT
for TMP05 Temperature 7.
5 R6T A 1 masks the
SMBALERT
for TMP05 Temperature 6.
4 R5T A 1 masks the
SMBALERT
for TMP05 Temperature 5.
3 R4T A 1 masks the
SMBALERT
for TMP05 Temperature 4.
2 R3T A 1 masks the
SMBALERT
for TMP05 Temperature 3.
1 R2T A 1 masks the
SMBALERT
for TMP05 Temperature 2.
0 R1T A 1 masks the
SMBALERT
for TMP05 Temperature 1.
Table 15. Interrupt Mask Register 2 (Register 0x73)
Bit No. Mnemonic Description
7
Fan 4
A 1 masks the
SMBALERT
for Fan 4 overspeed/underspeed conditions.
6 Fan 3 A 1 masks the
SMBALERT
for Fan 3 overspeed/underspeed conditions.
5 Fan 2 A 1 masks the
SMBALERT
for Fan 2 overspeed/underspeed conditions.
4 Fan 1 A 1 masks the
SMBALERT
for Fan 1 overspeed/underspeed conditions.
3 Unused Unused.
2 R10T A 1 masks the
SMBALERT
for TMP05 Temperature 10.
1 R9T A 1 masks the
SMBALERT
for TMP05 Temperature 9.
0 R8T A 1 masks the
SMBALERT
for TMP05 Temperature 8.