ATSAM3U-EK Atmel, ATSAM3U-EK Datasheet - Page 884

• Manufacturer Part Number: ATSAM3U-EK
• Description: KIT EVAL FOR AT91SAM3U CORTEX
• Manufacturer: Atmel
• Type: MCUr

Specifications of ATSAM3U-EK

• Contents: Board
• Processor To Be Evaluated: SAM3U
• Data Bus Width: 32 bit
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3 V
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Silicon Core Number: SAM3U4E
• Silicon Family Name: SAM3U
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT91SAM3U
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

38.6.3
884
884
SAM3U Series
SAM3U Series
PWM Comparison Units
The PWM provides 8 independent comparison units able to compare a programmed value with
the current value of the channel 0 counter (which is the channel counter of all synchronous
channels,
erate pulses on the event lines (used to synchronize ADC, see
Lines”), to generate software interrupts and to trigger PDC transfer requests for the synchronous
channels (see
update” on page
Figure 38-13. Comparison Unit Block Diagram
The comparison x matches when it is enabled by the bit CEN in the
Register”
the comparison value defined by the field CV in
(PWM_CMPVx for the comparison x). If the counter of the channel 0 is center aligned (CALG =
1 in
made when the counter is counting up or counting down (in left alignment mode CALG=0, this
bit is useless).
If a fault is active on the channel 0, the comparison is disabled and cannot match (see
38.6.2.5 ”Fault
The user can define the periodicity of the comparison x by the fields CTR and CPR (in
PWM_CMPVx). The comparison is performed periodically once every CPR+1 periods of the
counter of the channel 0, when the value of the comparison period counter CPRCNT (in
PWM_CMPMx) reaches the value defined by CTR. CPR is the maximum value of the compari-
son period counter CPRCNT. If CPR=CTR=0, the comparison is performed at each period of the
counter of the channel 0.
The comparison x configuration can be modified while the channel 0 is enabled by using the
“PWM Comparison x Mode Update Register”
x). In the same way, the comparison x value can be modified while the channel 0 is enabled by
using the
comparison x).
“PWM Channel Mode
(PWM_CMPMx for the comparison x) and when the counter of the channel 0 reaches
Section 38.6.2.6 ”Synchronous
“PWM Comparison x Value Update Register”
Protection”).
CEN [PWM_CMPM]x
fault on channel 0
CV [PWM_CMPVx]
CNT [PWM_CCNT0]
CNT [PWM_CCNT0] is decrementing
CVM [PWM_CMPVx]
CALG [PWM_CMR0]
CPRCNT [PWM_CMPMx]
CTR [PWM_CMPMx]
“Method 3: Automatic write of duty-cycle values and automatic trigger of the
881).
Register”), the bit CVM (in PWM_CMPVx) defines if the comparison is
Channels”). These comparisons are intended to gen-
=
=
=
(PWM_CMPMUPDx registers for the comparison
1
0
1
“PWM Comparison x Value Register”
(PWM_CMPVUPDx registers for the
Section 38.6.4 ”PWM Event
“PWM Comparison x Mode
Comparison x
6430D–ATARM–25-Mar-11
6430D–ATARM–25-Mar-11
Section