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
UM10316_0
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 00.06 — 17 December 2008
440 of 571
NXP Semiconductors
UM10316
Chapter 25: LPC29xx Pulse Width Modulator (PWM)
shows the bit assignment of the PRD register.
5.8 PWM prescale register
The PWM has a prescale register. The PWM counter increments after ‘PRSC + 1’
PWM clock cycles are counted.
shows the bit assignment of the PRSC register.
5.9 PWM synchronization delay register
The SYNDEL register allows delay of the trigger sync_out pin. Sync_out is generated
when the internal PWM counter matches the SYNDEL register and the prescale counter
overflows.
shows the bit assignment of the SYNDEL register.
5.10 PWM count register
The CNT register contains the current PWM value. When the PRSC register is zero the
PWM counter increments every system clock cycle: when the PRSC register value is
unequal to zero an internal prescale counter first counts the number of system clock
cycles as defined in this register plus one, then increments the PWM value.
shows the bit assignment of the CNT register.
Table 352. PRD register bit description
* = reset value
Bit
Symbol
Access
Value
Description
31 to 16 reserved
R
-
Reserved; do not modify. Read as logic 0
15 to 0
PRD
R/W
Period cycle minus 1
FFFFh*
Table 353. PRSC register bit description
* = reset value
Bit
Symbol
Access
Value
Description
31 to 16 reserved
R
-
Reserved; do not modify. Read as logic 0
15 to 0
PRSC
R/W
Prescaler value
FFFFh*
Table 354. SYNDEL register bit description
* = reset value
Bit
Symbol
Access
Value
Description
31 to 16 reserved
R
-
Reserved; do not modify. Read as logic 0
15 to 0
DLY
R/W
Value in system clock cycles of the delay
between the sync_in and sync_out pins
FFFFh*