AT32UC3A0512-ALTTA Atmel, AT32UC3A0512-ALTTA Datasheet - Page 203

• Manufacturer Part Number: AT32UC3A0512-ALTTA
• Description: IC MCU AVR32 512K FLASH 144LQFP
• Manufacturer: Atmel
• Series: AVR®32 UC3r

Specifications of AT32UC3A0512-ALTTA

• Core Processor: AVR
• Core Size: 32-Bit
• Speed: 66MHz
• Connectivity: EBI/EMI, Ethernet, I²C, SPI, SSC, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 109
• Program Memory Size: 512KB (512K 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: 144-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

23.7.3.7
Figure 23-8. Peripheral Deselection
32058J-AVR32-04/11
Write SPI_TDR
Write SPI_TDR
Write SPI_TDR
NPCS[0..3]
NPCS[0..3]
NPCS[0..3]
TDRE
TDRE
TDRE
Peripheral Deselection
A
A
A
DLYBCT
DLYBCT
DLYBCT
When operating normally, as soon as the transfer of the last data written in TDR is completed,
the NPCS lines all rise. This might lead to runtime error if the processor is too long in responding
to an interrupt, and thus might lead to difficulties for interfacing with some serial peripherals
requiring the chip select line to remain active during a full set of transfers.
To facilitate interfacing with such devices, the Chip Select Register can be programmed with the
CSAAT bit (Chip Select Active After Transfer) at 1. This allows the chip select lines to remain in
their current state (low = active) until transfer to another peripheral is required.
Figure 23-8
CSAAT = 0
DLYBCS
DLYBCS
DLYBCS
PCS = B
PCS=A
shows different peripheral deselection cases and the effect of the CSAAT bit.
PCS = A
A
B
A
A
A
A
DLYBCT
DLYBCT
DLYBCT
CSAAT = 1
DLYBCS
DLYBCS
PCS = B
PCS = A
A
A
PCS = A
DLYBCS
AT32UC3A
A
A
B
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