
DR
AFT
DR
AFT
DRAFT
DR
D
RAFT
DRAFT
DRA
FT DRAF
D
RAFT DRAFT DRAFT DRAFT DRAFT D
DRAFT
D
RAFT DRA
FT DRAFT DRAFT DRAFT DRA
UM10360_0
© NXP B.V. 2009. All rights reserved.
User manual
Rev. 00.06 — 5 June 2009
476 of 808
NXP Semiconductors
UM10360
Chapter 22: LPC17xx Repetitive Interrupt Timer (RIT)
Counting can be halted in software by writing a ‘0’ to the Enable_Timer bit - RICTRL(2).
Counting will also be halted while a hardware BREAK is in progress provided the
Enable_Break bit – RICTRL(1) is set. Both the Enable_Timer and Enable_Break bits are
set on reset.
The interrupt flag can be cleared in software by writing a ‘1’ to the Interrupt bit –
RICTRL(0).
Software can load the counter to any value at any time by writing to RICOUNTER.
The counter (RICOUNTER), RICOMPVAL register, RIMASK register and RICTRL register
can all be read by software at any time.
Fig 115. RI timer block diagram
32-bit COUNTER
CLR
ENA
COMPARATOR
COMPARE REGISTER
SET
MASK REGISTER
SET
3
2
S
C
CLR
EQ
0
ENABLE_TIMER
ENABLE_BREAK
BREAK
INTR
PBUS
PBUS
PBUS
RESET
RESET
RESET
SET_INT
32
32
32
32
PBUS
write '1' to
clear
PBUS
PBUS
PBUS
CLR
RESET
PBUS
PBUS
PBUS
CNT_ENA
CTRL
register
CLR
RESET
ENABLE_CLK
OperatingSystemTimer