AT91SAM7A3-AU Atmel, AT91SAM7A3-AU Datasheet - Page 398

• Manufacturer Part Number: AT91SAM7A3-AU
• Description: IC ARM7 MCU FLASH 256K 100LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7A3-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 60MHz
• Connectivity: CAN, I²C, MMC, SPI, SSC, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 62
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LQFP
• Controller Family/series: AT91SAM7xx
• No. Of I/o's: 62
• Ram Memory Size: 32KB
• Cpu Speed: 60MHz
• No. Of Timers: 3
• Rohs Compliant: Yes
• Package: 100LQFP
• Device Core: ARM7TDMI
• Family Name: 91S
• Maximum Speed: 60 MHz
• Operating Supply Voltage: 3.3 V
• Data Bus Width: 32 Bit
• Number Of Programmable I/os: 62
• Interface Type: CAN/SPI/I2S/TWI/USART/USB
• On-chip Adc: 2(8-chx10-bit)
• Number Of Timers: 3
• Processor Series: AT91SAMx
• Core: ARM7TDMI
• Data Ram Size: 32 KB
• Maximum Clock Frequency: 60 MHz
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM7A3-EK
• Minimum Operating Temperature: - 40 C
• Cpu Family: 91S
• Device Core Size: 32b
• Frequency (max): 60MHz
• Total Internal Ram Size: 32KB
• # I/os (max): 62
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 3V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 100
• Package Type: LQFP
• For Use With: AT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9AT91SAM7A3-EK - KIT EVAL FOR AT91SAM7A3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

32.5.3
32.5.3.1
32.5.3.2
32.5.3.3
398
AT91SAM7A3 Preliminary
PWM Controller Operations
Initialization
Source Clock Selection Criteria
Changing the Duty Cycle or the Period
Before enabling the output channel, this channel must have been configured by the software
application:
It is possible to synchronize different channels by enabling them at the same time by means of
writing simultaneously several CHIDx bits in the PWM_ENA register.
The large number of source clocks can make selection difficult. The relationship between the
value in the Period Register (PWM_CPRDx) and the Duty Cycle Register (PWM_CDTYx) can
help the user in choosing. The event number written in the Period Register gives the PWM
accuracy. The Duty Cycle quantum cannot be lower than 1/PWM_CPRDx value. The higher
the value of PWM_CPRDx, the greater the PWM accuracy.
For example, if the user sets 15 (in decimal) in PWM_CPRDx, the user is able to set a value
between 1 up to 14 in PWM_CDTYx Register. The resulting duty cycle quantum cannot be
lower than 1/15 of the PWM period.
It is possible to modulate the output waveform duty cycle or period.
To prevent unexpected output waveform, the user must use the update register
(PWM_CUPDx) to change waveform parameters while the channel is still enabled. The user
can write a new period value or duty cycle value in the update register (PWM_CUPDx). This
register holds the new value until the end of the current cycle and updates the value for the
next cycle. Depending on the CPD field in the PWM_CMRx register, PWM_CUPDx either
updates PWM_CPRDx or PWM_CDTYx. Note that even if the update register is used, the
period must not be smaller than the duty cycle.
• Configuration of the clock generator if DIVA and DIVB are required
• Selection of the clock for each channel (CPRE field in the PWM_CMRx register)
• Configuration of the waveform alignment for each channel (CALG field in the PWM_CMRx
• Configuration of the period for each channel (CPRD in the PWM_CPRDx register). Writing
• Configuration of the duty cycle for each channel (CDTY in the PWM_CDTYx register).
• Configuration of the output waveform polarity for each channel (CPOL in the PWM_CMRx
• Enable Interrupts (Writing CHIDx in the PWM_IER register)
• Enable the PWM channel (Writing CHIDx in the PWM_ENA register)
• In such a situation, all channels may have the same clock selector configuration and the
register)
in PWM_CPRDx Register is possible while the channel is disabled. After validation of the
channel, the user must use PWM_CUPDx Register to update PWM_CPRDx as explained
below.
Writing in PWM_CDTYx Register is possible while the channel is disabled. After validation
of the channel, the user must use PWM_CUPDx Register to update PWM_CDTYx as
explained below.
register)
same period specified.
6042E–ATARM–14-Dec-06