AT91SAM7S256C-MU Atmel, AT91SAM7S256C-MU Datasheet - Page 622

• 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

40.6.12.3
40.6.12.4
40.6.12.5
40.6.13
40.6.13.1
40.6.13.2
40.6.14
40.6.14.1
622
AT91SAM7S Series Preliminary
Voltage Regulator
Watchdog Timer (WDT)
USART: XOFF Character Bad Behavior
USART: RXBRK Flag Error in Asynchronous Mode
USART: DCD is active High instead of Low
Voltage Regulator: Current Consumption in Deep Mode
Voltage Regulator: Load Versus Temperature
WDT: The Watchdog Timer May Lock the Device in a Reset State
The XOFF character is sent only when the receive buffer is detected full. While the XOFF is
being sent, the remote transmitter is still transmitting. As only one Holding register is available in
the receiver, characters will be lost in reception. This makes the software handshaking function-
ality ineffective.
None.
In receiver mode, when there are two consecutive characters (without timeguard in between),
RXBRK is not taken into account. As a result, the RXBRK flag is not enabled correctly and the
frame error flag is set.
Constraints on the transmitter device connected to the AT91SAM7S USART receiver side:
The transmitter may use the timeguard feature or send two STOP conditions. Only one STOP
condition is taken into account by the receiver state machine. After this STOP condition, as there
is no valid data, the receiver state machine will go in idle mode and enable the RXBRK flag.
The DCD signal is active at High level in the USART Modem Mode.
DCD should be active at Low level.
Add an inverter.
Current consumption in Deep Mode is maximum 60 µA instead of 25 µA.
Due to current rejection from VDDIN to VDDCORE, the current consumption in Deep Mode can-
not be guaranteed. Instead, 60 µA is guaranteed whatever the condition.
None.
Maximum load is 50 mA at 85 °C (instead of 100 mA).
Maximum load is 100 mA at 70°C.
None.
Under certain rare circumstances, if the Watchdog Timer is used with the Watchdog Reset
enabled (WDRSTEN set at 1), the Watchdog Timer may lock the device in a reset state when
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
6175K–ATARM–30-Aug-10