DRAFT
DRAFT DRAFT DR
DRAFT DRAFT DRAFT
D
RAF
DRAFT DRAFT DRA
FT D
RAFT DR
AFT D
DRA
FT DRAFT DRAFT
D
RAFT
DRAFT
D
RAFT
DRA
UM10601
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
Preliminary user manual
Rev. 1.0 — 7 November 2012
118 of 313
NXP Semiconductors
UM10601
Chapter 10: LPC800 State Configurable Timer (SCT)
10.6.2 SCT control register
If UNIFY = 1 in the CONFIG register, only the _L bits are used.
If UNIFY = 0 in the CONFIG register, this register can be written to as two registers
CTRL_L and CTRL_H. Both the L and H registers can be read or written individually or in
a single 32-bit read or write operation.
All bits in this register can be written to when the counter is stopped or halted. When the
counter is running, the only bits that can be written are STOP or HALT. (Other bits can be
written in a subsequent write after HALT is set to 1.)
16:9
INSYNC
-
Synchronization for input N (bit 9 = input 0, bit 10 = input 1,..., bit 16 = input 7).
A 1 in one of these bits subjects the corresponding input to synchronization to
the SCT clock, before it is used to create an event. If an input is synchronous to
the SCT clock, keep its bit 0 for faster response.
When the CKMODE field is 1x, the bit in this field, corresponding to the input
selected by the CKSEL field, is not used.
1
17
AUTOLIMIT_L
-
A one in this bit causes a match on match register 0 to be treated as a de-facto
LIMIT condition without the need to define an associated event.
As with any LIMIT event, this automatic limit causes the counter to be cleared to
zero in uni-directional mode or to change the direction of count in bi-directional
mode.
Software can write to set or clear this bit at any time. This bit applies to both the
higher and lower registers when the UNIFY bit is set.
18
AUTOLIMIT_H
-
A one in this bit will cause a match on match register 0 to be treated as a
de-facto LIMIT condition without the need to define an associated event.
As with any LIMIT event, this automatic limit causes the counter to be cleared to
zero in uni-directional mode or to change the direction of count in bi-directional
mode.
Software can write to set or clear this bit at any time. This bit is not used when
the UNIFY bit is set.
31:19
-
Reserved
-
Table 108. SCT configuration register (CONFIG, address 0x5000 4000) bit description
…continued
Bit
Symbol
Value
Description
Reset
value
Table 109. SCT control register (CTRL, address 0x5000 4004) bit description
Bit
Symbol
Value
Description
Reset
value
0
DOWN_L
-
This bit is 1 when the L or unified counter is counting down. Hardware sets this bit
when the counter limit is reached and BIDIR is 1. Hardware clears this bit when the
counter is counting down and a limit condition occurs or when the counter reaches 0.
0
1
STOP_L
-
When this bit is 1 and HALT is 0, the L or unified counter does not run, but I/O events
related to the counter can occur. If such an event matches the mask in the Start
register, this bit is cleared and counting resumes.
0
2
HALT_L
-
When this bit is 1, the L or unified counter does not run and no events can occur. A
reset sets this bit. When the HALT_L bit is one, the STOP_L bit is cleared. If you
want to remove the halt condition and keep the SCT in the stop condition (not
running), then you can change the halt and stop condition with one single write to
this register.
Remark:
Once set, only software can clear this bit to restore counter operation.
1