ST10F280 STMicroelectronics, ST10F280 Datasheet - Page 63

• Manufacturer Part Number: ST10F280
• Description: MCU 16BIT 512K FLASH MAC 208-PBG
• Manufacturer: STMicroelectronics
• Series: ST10r

Specifications of ST10F280

• Core Processor: ST10
• Core Size: 16-Bit
• Speed: 40MHz
• Connectivity: ASC, CAN, EBI/EMI, SSC
• Peripherals: POR, PWM, WDT
• Number Of I /o: 143
• Program Memory Size: 512KB (512K x 8)
• Program Memory Type: FLASH
• Ram Size: 18K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 32x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 208-PBGA
• Processor Series: ST10F28x
• Core: ST10
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

11.2.1.2 - Mode 1: Symmetrical PWM
Generation (Center Aligned PWM)
Mode 1 is selected by setting the respective bit
XPMx in register XPWMCON1 to ‘1’. In this mode
the timer XPTx of the respective XPWM channel
is counting up until it reaches the value in the
associated period shadow register.
Upon the next count pulse the count direction is
reversed and the timer starts counting down now
with subsequent count pulses until it reaches the
value 0000
direction is reversed again and the count cycle is
repeated with the following count pulses.
The XPWM output signal is switched to a high
level when the timer contents are equal to or
greater than the contents of the pulse width
shadow register while the timer is counting up.
Figure 21 : Operation and Output Waveform in Mode 1
XPTx Count
Value
XPWx Pulse
Width=0
XPWx=1
XPWx=2
XPWx=4
XPWx=6
XPWx=7
XPWx=8
XPPx
Period=7
H
. Upon the next count pulse the count
Latch Shadow Registers
2
Interrupt Reques
1
0
LSR
0
1
2
3
4
5
Change Count
6
Direction
7
7
The signal is switched back to a low level when
the respective timer has counted down to a value
below the contents of the pulse width shadow reg-
ister. So in mode 1 this PWM value controls both
edges of the output signal.
Note that in mode 1 the period of the PWM signal
is twice the period of the timer:
The figure below illustrates the operation and out-
put waveforms of a XPWM channel in mode 1 for
different values in the pulse width register.
This mode is referred to as Center Aligned PWM,
because the value in the pulse width (shadow)
register effects both edges of the output signal
symmetrically.
6
5
PWM_Period
4
3
2
1
Mode1
LSR
0
= 2 * ([XPPx] + 1)
1
Duty Cycle
100%
87.5%
75%
50%
25%
12.5%
0%
ST10F280
63/186