
UM10800
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User manual
Rev. 1.2 — 5 October 2016
279 of 487
NXP Semiconductors
UM10800
Chapter 16: LPC82x SCTimer/PWM
16.6.15 SCT DMA request 0 and 1 registers
The SCT includes two DMA request outputs. These registers enable the DMA requests to
be triggered when a particular event occurs or when counter Match registers are loaded
from its Reload registers. The DMA request registers are word-write only. Attempting to
write a half-word value to these registers result in a bus error.
Event-triggered DMA requests are particularly useful for launching DMA activity to or from
other peripherals under the control of the SCT.
16.6.16 SCT event interrupt enable register
This register enables flags to request an interrupt if the FLAGn bit in the SCT event flag
register (
) is also set.
Table 236. SCT DMA 0 request register (DMAREQ0, address 0x5000 405C) bit description
Bit
Symbol
Description
Reset
value
5:0
DEV_0
If bit n is one, event n triggers DMA request 0 (event 0 = bit 0,
event 1 = bit 1,..., event 7 = bit 7).
0
29:6
-
Reserved
-
30
DRL0
A 1 in this bit triggers DMA request 0 when it loads the
Match_L/Unified registers from the Reload_L/Unified registers.
31
DRQ0
This read-only bit indicates the state of DMA Request 0.
Note that if the related DMA channel is enabled and properly set
up, it is unlikely that software will see this flag, it will be cleared
rapidly by the DMA service. The flag remaining set could point
to an issue with DMA setup.
Table 237. SCT DMA 1 request register (DMAREQ1, address 0x5000 C060) bit description
Bit
Symbol
Description
Reset
value
5:0
DEV_1
If bit n is one, event n triggers DMA request 1 (event 0 = bit 0,
event 1 = bit 1,..., event 7 = bit 7).
0
29:6
-
Reserved
-
30
DRL1
A 1 in this bit triggers DMA request 1 when it loads the Match
L/Unified registers from the Reload L/Unified registers.
31
DRQ1
This read-only bit indicates the state of DMA Request 1.
Note that if the related DMA channel is enabled and properly set
up, it is unlikely that software will see this flag, it will be cleared
rapidly by the DMA service. The flag remaining set could point
to an issue with DMA setup.
Table 238. SCT event interrupt enable register (EVEN, address 0x5000 40F0) bit description
Bit
Symbol
Description
Reset
value
7:0
IEN
The SCT requests an interrupt when bit n of this register and the
event flag register are both one (event 0 = bit 0, event 1 = bit 1,...,
event 7 = bit 7).
0
31:8
-
Reserved