AT91SAM7S32B-AU Atmel, AT91SAM7S32B-AU Datasheet - Page 500

• Manufacturer Part Number: AT91SAM7S32B-AU
• Description: IC MCU ARM7 32KB FLASH 48LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7S32B-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: I²C, SPI, SSC, UART/USART
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 21
• 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: 48-LQFP
• Cpu Family: 91S
• Device Core: ARM7TDMI
• Device Core Size: 32b
• Frequency (max): 55MHz
• Interface Type: SPI/TWI/USART
• Total Internal Ram Size: 8KB
• # I/os (max): 21
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 1.8/3.3V
• Operating Supply Voltage (max): 1.95/3.6V
• Operating Supply Voltage (min): 1.65/3V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 48
• Package Type: LQFP
• Package: 48LQFP
• Family Name: AT91
• Maximum Speed: 55 MHz
• Operating Supply Voltage: 1.8|3.3 V
• Data Bus Width: 32 Bit
• Number Of Programmable I/os: 21
• Number Of Timers: 3
• 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: Compliant

35.4
35.4.1
35.4.2
500
Typical Connection
AT91SAM7S Series Preliminary
USB Device Transceiver
VBUS Monitoring
Figure 35-2. Board Schematic to Interface USB Device Peripheral
The USB device transceiver is embedded in the product. A few discrete components are
required as follows:
Pullup enable/disable is done through a MOSFET controlled by a PIO. The pullup is enabled
when the PIO drives a 0. Thus PIO default state to 1 corresponds to a pullup disable. Once the
pullup is enabled, the host will force a device reset 100 ms later. Bus powered devices must
connect the pullup within 100 ms.
VBUS monitoring is required to detect host connection. VBUS monitoring is done using a stan-
dard PIO with internal pullup disabled. When the host is switched off, it should be considered as
a disconnect, the pullup must be disabled in order to prevent powering the host through the pull-
up resistor.
When the host is disconnected and the transceiver is enabled, then DDP and DDM are floating.
This may lead to over consumption. A solution is to connect 330 KΩ pulldowns on DP and DM.
These pulldowns do not alter DDP and DDM signal integrity.
PIO
PIO
DDM
DDP
• the application detects all device states as defined in chapter 9 of the USB specification;
• to reduce power consumption the host is disconnected
• for line termination.
– pullup enable/disable
– VBUS monitoring
5V Bus Monitoring
Pullup Control
0: Enable
1: Disable
47 K
27 K
R
R
EXT
EXT
330 K
330 K
3V3
1.5K
2
3
Connector
6175K–ATARM–30-Aug-10
Type B
1
4