AT91SAM7A3-AU Atmel, AT91SAM7A3-AU Datasheet - Page 279

• 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

Table 29-2.
29.5.1.3
6042E–ATARM–14-Dec-06
Source Clock
14 318 180
14 745 600
18 432 000
24 000 000
24 576 000
25 000 000
32 000 000
32 768 000
33 000 000
40 000 000
50 000 000
Baud Rate in Synchronous Mode
Baud Rate Example (OVER = 0) (Continued)
Expected Baud
The baud rate is calculated with the following formula:
The baud rate error is calculated with the following formula. It is not recommended to work
with an error higher than 5%.
If the USART is programmed to operate in synchronous mode, the selected clock is simply
divided by the field CD in US_BRGR.
In synchronous mode, if the external clock is selected (USCLKS = 3), the clock is provided
directly by the signal on the USART SCK pin. No division is active. The value written in
US_BRGR has no effect. The external clock frequency must be at least 4.5 times lower than
the system clock.
When either the external clock SCK or the internal clock divided (MCK/DIV) is selected, the
value programmed in CD must be even if the user has to ensure a 50:50 mark/space ratio on
the SCK pin. If the internal clock MCK is selected, the Baud Rate Generator ensures a 50:50
duty cycle on the SCK pin, even if the value programmed in CD is odd.
38 400
38 400
38 400
38 400
38 400
38 400
38 400
38 400
38 400
38 400
38 400
Rate
BaudRate
Error
BaudRate
=
Calculation Result
1
–
=
=
⎛
⎝
SelectedClock
------------------------------------- -
ExpectedBaudRate
-------------------------------------------------- -
MCK CD
ActualBaudRate
23.30
24.00
30.00
39.06
40.00
40.69
52.08
53.33
53.71
65.10
81.38
CD
⁄
×
16
⎞
⎠
CD
23
24
30
39
40
40
52
53
54
65
81
AT91SAM7A3 Preliminary
Actual Baud Rate
38 908.10
38 400.00
38 400.00
38 461.54
38 400.00
38 109.76
38 461.54
38 641.51
38 194.44
38 461.54
38 580.25
1.31%
0.00%
0.00%
0.16%
0.00%
0.76%
0.16%
0.63%
0.54%
0.16%
0.47%
Error
279