UM10503
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User manual
Rev. 1.3 — 6 July 2012
855 of 1269
NXP Semiconductors
UM10503
Chapter 29: LPC43xx Timer0/1/2/3
29.6.4 Timer prescale registers
The 32-bit Timer prescale register specifies the maximum value for the Prescale Counter.
29.6.5 Timer prescale counter registers
The 32-bit Prescale Counter controls division of PCLK by some constant value before it is
applied to the Timer Counter. This allows control of the relationship of the resolution of the
timer versus the maximum time before the timer overflows. The Prescale Counter is
incremented on every PCLK. When it reaches the value stored in the Prescale register,
the Timer Counter is incremented and the Prescale Counter is reset on the next PCLK.
This causes the Timer Counter to increment on every PCLK when PR = 0, every 2 PCLKs
when PR = 1, etc.
29.6.6 Timer match control registers
The Match Control Register is used to control what operations are performed when one of
the Match Registers matches the Timer Counter. The function of each of the bits is shown
in
Table 686. Timer counter registers (TC - addresses 0x4008 4008 (TIMER0), 0x4008 5008
(TIMER1), 0x400C 3008 (TIMER2), 0x400C 4008 (TIMER3)) bit description
Bit
Symbol
Description
Reset
value
31:0
TC
Timer counter value.
0
Table 687. Timer prescale registers (PR - addresses 0x4008 400C (TIMER0), 0x4008 500C
(TIMER1), 0x400C 300C (TIMER2), 0x400C 400C (TIMER3)) bit description
Bit
Symbol
Description
Reset
value
31:0
PM
Prescale counter maximum value.
0
Table 688. Timer prescale counter registers (PC - addresses 0x4008 4010 (TIMER0),
0x4008 5010 (TIMER1), 0x400C 3010 (TIMER2), 0x400C 4010 (TIMER3)) bit
description
Bit
Symbol
Description
Reset
value
31:0
PC
Prescale counter value.
0
Table 689. Timer match control registers (MCR - addresses 0x4008 4014 (TIMER0),
0x4008 5014 (TIMER1), 0x400C 3014 (TIMER2), 0x400C 4014 (TIMER3)) bit
description
Bit
Symbol Value Description
Reset
value
0
MR0I
Interrupt on MR0
0
1
Interrupt is generated when MR0 matches the value in the TC.
0
Interrupt is disabled
1
MR0R
Reset on MR0
0
1
TC will be reset if MR0 matches it.
0
Feature disabled.