AT91SAM7S256C-MU Atmel, AT91SAM7S256C-MU Datasheet - Page 485

• Manufacturer Part Number: AT91SAM7S256C-MU
• Description: IC ARM7 MCU 32BIT 256K 64-QFN
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7S256C-MU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 64K 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: 64-VQFN Exposed Pad, 64-HVQFN, 64-SQFN, 64-DHVQFN
• Processor Series: AT91
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 64 KB
• Interface Type: SPI, TWI, USART, USB
• Maximum Clock Frequency: 55 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 5
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 85 C
• For Use With: AT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9AT91SAM7S-EK - KIT EVAL FOR ARM AT91SAM7S
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: AT91SAM7S256-MU; AT91SAM7S256-MU

6175K–ATARM–30-Aug-10
Figure 34-6. Synchronized Period or Duty Cycle Update
To prevent overwriting the PWM_CUPDx by software, the user can use status events in order to
synchronize his software. Two methods are possible. In both, the user must enable the dedi-
cated interrupt in PWM_IER at PWM Controller level.
The first method (polling method) consists of reading the relevant status bit in PWM_ISR Regis-
ter according to the enabled channel(s). See
The second method uses an Interrupt Service Routine associated with the PWM channel.
Note:
Figure 34-7. Polling Method
Note:
Reading the PWM_ISR register automatically clears CHIDx flags.
Polarity and alignment can be modified only when the channel is disabled.
End of Cycle
Acknowledgement and clear previous register state
The last write has been taken into account
PWM_CPRDx
Update of the Period or Duty Cycle
Writing in PWM_CUPDx
AT91SAM7S Series Preliminary
PWM_CUPDx Value
Writing in CPD field
PWM_ISR Read
1
User's Writing
CHIDx = 1
Figure
YES
PWM_CDTYx
0
34-7.
PWM_CMRx. CPD
485