Datasheet

© 2009 Microchip Technology Inc. DS22153C-page 21
MCP9843/98243
bit 7 T
CRIT
Lock Bit (Crit. Lock):
0 = Unlocked. T
CRIT
register can be written. (power-up default)
1 = Locked. T
CRIT
register can not be written
When enabled, this bit remains set ‘1’ or locked until cleared by internal reset (Section 5.4 “Summary
of Power-on Default”). This bit does not require a double-write.
This bit can be programmed in shutdown mode.
bit 6 T
UPPER
and T
LOWER
Window Lock Bit (Win. Lock):
0 = Unlocked. T
UPPER
and T
LOWER
registers can be written. (power-up default)
1 = Locked. T
UPPER
and T
LOWER
registers can not be written
When enabled, this bit remains set ‘1’ or locked until cleared by power-on Respell (Section 5.4 “Sum-
mary of Power-on Default”). This bit does not require a double-write.
This bit can be programmed in shutdown mode.
bit 5 Interrupt Clear (Int. Clear) Bit:
0 = No effect (power-up default)
1 = Clear interrupt output. When read this bit returns ‘0’
This bit clears the Interrupt flag which de-asserts Event output. In shutdown mode, the Event output is
always de-asserted. Therefore, setting this bit in shutdown mode clears the interrupt after the device
returns to normal operation.
bit 4 Event Output Status (Event Stat.) Bit:
0 = Event output is not asserted by the device (power-up default)
1 = Event output is asserted as a comparator/Interrupt or critical temperature output
In shutdown mode this bit will clear because Event output is always de-asserted in shutdown mode.
bit 3 Event Output Control (Event Cnt.) Bit:
0 = Event output Disabled (power-up default)
1 = Event output Enabled
This bit can not be altered when either of the lock bits is set (bit 6 and bit 7).
This bit can be programmed in shutdown mode, but Event output will remain de-asserted.
bit 2 Event Output Select (Event Sel.) Bit:
0 = Event output for T
UPPER
, T
LOWER
and T
CRIT
(power-up default)
1 = T
A
≥ T
CRIT
only. (T
UPPER
and T
LOWER
temperature boundaries are disabled.)
When the Alarm Window Lock bit is set, this bit cannot be altered until unlocked (bit 6).
This bit can be programmed in shutdown mode, but Event output will remain de-asserted.
bit 1 Event Output Polarity (Event Pol.) Bit:
0 = Active low (power-up default. Pull-up resistor required) See Section 5.2.3 “Event Output
Configuration”
1 = Active-high (Pull-down resistor required) See Section 5.2.3 “Event Output Configuration”
This bit cannot be altered when either of the lock bits is set (bit 6 and bit 7).
This bit can be programmed in shutdown mode, but Event output will remain de-asserted.
bit 0 Event Output Mode (Event Mod.) Bit:
0 = Comparator output (power-up default)
1 = Interrupt output
This bit cannot be altered when either of the lock bits is set (bit 6 and bit 7).
This bit can be programmed in shutdown mode, but Event output will remain de-asserted.
REGISTER 5-3: CONFIGURATION REGISTER (CONFIG) → ADDRESS ‘0000 0001’b