AT32UC3B1256-Z1UR Atmel, AT32UC3B1256-Z1UR Datasheet - Page 175

• Manufacturer Part Number: AT32UC3B1256-Z1UR
• Description: MCU AVR32 256K FLASH 48-QFN
• Manufacturer: Atmel
• Series: AVR®32 UC3r

Specifications of AT32UC3B1256-Z1UR

• Package / Case: 48-QFN Exposed Pad
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Operating Temperature: -40°C ~ 85°C
• Speed: 60MHz
• Number Of I /o: 28
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Program Memory Size: 256KB (256K x 8)
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Connectivity: I²C, IrDA, SPI, SSC, UART/USART, USB
• Core Size: 32-Bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

17.5.1.4
17.5.1.5
17.5.2
17.5.2.1
17.5.2.2
32059J–12/2010
Advanced Operation
Inputs
Output line timings
Pull-up resistor control
Input glitch filter
responding I/O line is driven by the GPIO. When the bit is written to zero, the GPIO does not
drive the line.
The level driven on an I/O line can be determined by writing to the Output Value Register (OVR).
The level on each I/O line can be read through the Pin Value Register (PVR). This register indi-
cates the level of the I/O lines regardless of whether the lines are driven by the GPIO or by an
external component. Note that due to power saving measures, the PVR register can only be
read when GPER is written to one for the corresponding pin or if interrupt is enabled for the pin.
The figure below shows the timing of the I/O line when writing a one and a zero to OVR. The
same timing applies when performing a ‘set’ or ‘clear’ access, i.e., writing a one to the Output
Value Set Register (OVRS) or the Output Value Clear Register (OVRC). The timing of PVR is
also shown.
Figure 17-3. Output Line Timings
Each I/O line is designed with an embedded pull-up resistor. The pull-up resistor can be enabled
or disabled by writing a one or a zero to the corresponding bit in the Pull-up Enable Register
(PUER). Control of the pull-up resistor is possible whether an I/O line is controlled by a periph-
eral or the GPIO.
Optional input glitch filters can be enabled on each I/O line. When the glitch filter is enabled, a
glitch with duration of less than 1 clock cycle is automatically rejected, while a pulse with dura-
tion of 2 clock cycles or more is accepted. For pulse durations between 1 clock cycle and 2 clock
cycles, the pulse may or may not be taken into account, depending on the precise timing of its
occurrence. Thus for a pulse to be guaranteed visible it must exceed 2 clock cycles, whereas for
a glitch to be reliably filtered out, its duration must not exceed 1 clock cycle. The filter introduces
2 clock cycles of latency.
The glitch filters are controlled by the Glitch Filter Enable Register (GFER). When a bit is written
to one in GFER, the glitch filter on the corresponding pin is enabled. The glitch filter affects only
interrupt inputs. Inputs to peripherals or the value read through PVR are not affected by the
glitch filters.
Write OVR to 1
Write OVR to 0
OVR / I/O Line
CLK_GPIO
PVR
PB Access
PB Access
AT32UC3B
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