AT91SAM7S321-AU Atmel, AT91SAM7S321-AU Datasheet - Page 409

• Manufacturer Part Number: AT91SAM7S321-AU
• Description: IC ARM7 MCU FLASH 32K 64LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7S321-AU

• 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: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K 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-LQFP
• Processor Series: AT91SAMx
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 8 KB
• Interface Type: I2C, I2S, SPI, SSC, TWI, UART, USB
• Maximum Clock Frequency: 55 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 10 bit
• Operating Supply Voltage: 1.8 V to 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, KSK-AT91SAM7S-PL, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM7S-EK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Controller Family/series: AT91SAM7xxxx
• No. Of I/o's: 32
• Ram Memory Size: 8KB
• Cpu Speed: 55MHz
• No. Of Timers: 3
• Rohs Compliant: Yes
• 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: Lead free / RoHS Compliant

32.6.1.1
32.6.1.2
6175K–ATARM–30-Aug-10
Clock Divider
Transmitter Clock Management
Figure 32-4. Divided Clock Block Diagram
The Master Clock divider is determined by the 12-bit field DIV counter and comparator (so its
maximal value is 4095) in the Clock Mode Register SSC_CMR, allowing a Master Clock division
by up to 8190. The Divided Clock is provided to both the Receiver and Transmitter. When this
field is programmed to 0, the Clock Divider is not used and remains inactive.
When DIV is set to a value equal to or greater than 1, the Divided Clock has a frequency of Mas-
ter Clock divided by 2 times DIV. Each level of the Divided Clock has a duration of the Master
Clock multiplied by DIV. This ensures a 50% duty cycle for the Divided Clock regardless of
whether the DIV value is even or odd.
Figure 32-5.
Table 32-2.
The transmitter clock is generated from the receiver clock or the divider clock or an external
clock scanned on the TK I/O pad. The transmitter clock is selected by the CKS field in
SSC_TCMR (Transmit Clock Mode Register). Transmit Clock can be inverted independently by
the CKI bits in SSC_TCMR.
Maximum
MCK / 2
Divided Clock Generation
Divided Clock
Divided Clock
Master Clock
Master Clock
DIV = 3
DIV = 1
MCK
AT91SAM7S Series Preliminary
/ 2
Divided Clock Frequency = MCK/2
Divided Clock Frequency = MCK/6
Clock Divider
12-bit Counter
MCK / 8190
Minimum
SSC_CMR
Divided Clock
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