AT91SAM7S256D-AU Atmel, AT91SAM7S256D-AU Datasheet - Page 483

• Manufacturer Part Number: AT91SAM7S256D-AU
• Description: ARM Microcontrollers - MCU 256K Flash SRAM 64K ARM based MCU
• Manufacturer: Atmel
• Series: SAM7S256r

Specifications of AT91SAM7S256D-AU

• Rohs: yes
• Core: ARM
• Processor Series: AT91SAM
• Data Bus Width: 16 bit/32 bit
• Maximum Clock Frequency: 55 MHz
• Program Memory Size: 256 KB
• Data Ram Size: 64 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 3 V to 3.6 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: LQFP-64
• Mounting Style: SMD/SMT
• Interface Type: 2-Wire, I2S, SPI, USART
• Length: 7 mm

34.5.1
Figure 34-2. Functional View of the Clock Generator Block Diagram
Caution: Before using the PWM macrocell, the programmer must first enable the PWM clock in the Power Man-
agement Controller (PMC).
The PWM macrocell master clock, MCK, is divided in the clock generator module to provide different clocks avail-
able for all channels. Each channel can independently select one of the divided clocks.
The clock generator is divided in three blocks:
Each linear divider can independently divide one of the clocks of the modulo n counter. The selection of the clock
to be divided is made according to the PREA (PREB) field of the PWM Mode register (PWM_MR). The resulting
clock clkA (clkB) is the clock selected divided by DIVA (DIVB) field value in the PWM Mode register (PWM_MR).
After a reset of the PWM controller, DIVA (DIVB) and PREA (PREB) in the PWM Mode register are set to 0. This
implies that after reset clkA (clkB) are turned off.
PWM Clock Generator
– a modulo n counter which provides 11 clocks: F
– two linear dividers (1, 1/2, 1/3, ... 1/255) that provide two separate clocks: clkA and clkB
F
MCK
/64, F
MCK
/128, F
MCK
/256, F
MCK
MCK
modulo n counter
/512, F
MCK
/1024
PREA
MCK
PREB
PWM_MR
PWM_MR
, F
Divider A
Divider B
MCK
DIVA
DIVB
/2, F
MCK
MCK/2
MCK/4
MCK/8
MCK/16
MCK/32
MCK/64
MCK/128
MCK/256
MCK/512
MCK/1024
MCK
/4, F
clkA
clkB
SAM7S Series [DATASHEET]
MCK
/8, F
MCK
/16, F
6175M–ATARM–26-Oct-12
MCK
/32,
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