DSPIC30F3011-30I/PT Microchip Technology Inc., DSPIC30F3011-30I/PT Datasheet - Page 107

• Manufacturer Part Number: DSPIC30F3011-30I/PT
• Description: 16 BIT MCU/DSP 44LD 30MIPS 24 KB FLASH
• Manufacturer: Microchip Technology Inc.
• Type: DSPr

Specifications of DSPIC30F3011-30I/PT

• A/d Inputs: 9-Channels, 10-Bit
• Cpu Speed: 30 MIPS
• Eeprom Memory: 1K Bytes
• Input Output: 30
• Interface: I2C/SPI/UART, USART
• Ios: 30
• Memory Type: Flash
• Number Of Bits: 16
• Package Type: 44-pin TQFP
• Programmable Memory: 24K Bytes
• Ram Size: 1K Bytes
• Timers: 5-16-bit, 2-32-bit
• Voltage, Range: 2.5-5.5
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

15.1.5
The input clock to PTMR (F
options of 1:1, 1:4, 1:16, or 1:64, selected by control
bits PTCKPS<1:0> in the PTCON SFR. The prescaler
counter is cleared when any of the following occurs:
• a write to the PTMR register
• a write to the PTCON register
• any device Reset
The PTMR register is not cleared when PTCON is
written.
15.1.6
The match output of PTMR can optionally be post-
scaled through a 4-bit postscaler (which gives a 1:1 to
1:16 scaling).
The postscaler counter is cleared when any of the
following occurs:
• a write to the PTMR register
• a write to the PTCON register
• any device Reset
The PTMR register is not cleared when PTCON is written.
15.2
PTPER is a 15-bit register and is used to set the count-
ing period for the PWM time base. PTPER is a double
buffered register. The PTPER buffer contents are
loaded into the PTPER register at the following instants:
• Free Running and Single Shot modes: When the
• Up/Down Counting modes: When the PTMR
The value held in the PTPER buffer is automatically
loaded into the PTPER register when the PWM time
base is disabled (PTEN = 0).
The
Equation 15-1:
EQUATION 15-1:
If the PWM time base is configured for one of the Up/
Down Count modes, the PWM period will be twice the
value provided by Equation 15-1.
 2004 Microchip Technology Inc.
Note: PWM period will be twice the value provided
by this equation when using center aligned modes.
PTMR register is reset to zero after a match with
the PTPER register.
register is zero.
PWM
PWM Period
T
PWM
PWM TIME BASE PRESCALER
PWM TIME BASE POSTSCALER
period
=
(PTMR Prescale Value)
T
PWM PERIOD
CY
can
•
(PTPER + 1)
be
OSC
determined
/4), has prescaler
using
Preliminary
The maximum resolution (in bits) for a given device
oscillator and PWM frequency can be determined using
Equation 15-2:
EQUATION 15-2:
15.3
Edge aligned PWM signals are produced by the module
when the PWM time base is in the Free Running or Sin-
gle Shot mode. For edge aligned PWM outputs, the out-
put has a period specified by the value in PTPER and a
duty cycle specified by the appropriate duty cycle regis-
ter (see Figure 15-3). The PWM output is driven active
at the beginning of the period (PTMR = 0) and is driven
inactive when the value in the duty cycle register
matches PTMR.
If the value in a particular duty cycle register is zero,
then the output on the corresponding PWM pin will be
inactive for the entire PWM period. In addition, the out-
put on the PWM pin will be active for the entire PWM
period if the value in the duty cycle register is greater
than the value held in the PTPER register.
FIGURE 15-3:
15.4
Center aligned PWM signals are produced by the mod-
ule when the PWM time base is configured in an Up/
Down Counting mode (see Figure 15-4).
The PWM compare output is driven to the active state
when the value of the duty cycle register matches the
value of PTMR and the PWM time base is counting
downwards (PTDIR = 1). The PWM compare output is
driven to the inactive state when the PWM time base is
counting upwards (PTDIR = 0) and the value in the
PTMR register matches the duty cycle value.
PTPER
0
Resolution =
Edge Aligned PWM
Center Aligned PWM
PTMR
Value
Duty Cycle
Period
PWM RESOLUTION
EDGE ALIGNED PWM
log (2
New Duty Cycle Latched
dsPIC30F
log (2)
•
T
PWM
DS70082G-page 105
/ T
CY
)