UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
133 of 362
NXP Semiconductors
UM10208
Chapter 11: LPC2800 WDT
4.5 Watchdog Match Control Register (WDT_MCR - 0x8000 2814)
This register controls what happens when the Timer Counter is equal to Match Control
Register 0 at a WDT clock edge.
4.6 Watchdog Match Register 0 (WDT_MR0 - 0x8000 2818)
The value in this register controls what value of the Timer Counter will set bit 0 in the
WDT_SR and/or request an interrupt.
4.7 Watchdog Match Register 1 (WDT_MR1 - 0x8000 281C)
The value in this register controls what value of the Timer Counter will set bit 1 in the
WDT_SR and/or cause the LPC288x to be reset.
Table 134: Watchdog Match Control Register (WDT_MCR - 0x8000 2814)
Bit
Function
Description
Reset Value
0
Enable
MR0 Status
Set this bit to 1 so that bit 0 of the WDT_SR is set when the
Timer Counter matches MR0.
0
1
Reset on
MR0 Match
When this bit is 1, the Timer Counter is reset when it matches
MR0. For Watchdog applications, leave this bit 0 so that the TC
can continue on to the MR1 (Reset) value.
0
2
Stop on
MR0 Match
When this bit is 1, bit 0 (Counter Enable) in the WDT_TCR is
cleared when the TC matches MR0, so that further counting is
disabled. For Watchdog applications, leave this bit 0 so that the
TC can continue on to the MR1 (Reset) value.
0
3
Enable
MR1 Status
If this bit is 1, bit 1 of the WDT_SR is set when the Timer
Counter matches MR1. If this event causes the LPC288x to be
reset, there is no reason to set this bit.
0
4
Reset on
MR1 Match
When this bit is 1, the Timer Counter is reset when it matches
MR1. If this event causes the LPC288x to be reset, there is no
reason to set this bit.
0
5
Stop on
MR1 Match
When this bit is 1, bit 0 (Counter Enable) in the WDT_TCR is
cleared when the TC matches MR1, so that further counting is
disabled. If this event causes the LPC288x to be reset, there is
no reason to set this bit.
0
31:6 -
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
-
Table 135: Watchdog Match Register 0 (WDT_MR0 - 0x8000 2818)
Bit
Function
Description
Reset Value
31:0
Value of the Timer Counter at which to set bit 0 of the WDT_SR,
and/or request an interrupt.
0
Table 136: Watchdog Match Register 1 (WDT_MR1 - 0x8000 281C)
Bit
Function
Description
Reset Value
31:0
Value of the Timer Counter at which to the LPC288x can be
reset.
0