ATA6613 ATMEL Corporation, ATA6613 Datasheet - Page 229

• Manufacturer Part Number: ATA6613
• Description: Ata6613
• Manufacturer: ATMEL Corporation

6.18.7
9111C–AUTO–02/08
AVR USART MSPIM versus AVR SPI
The USART in MSPIM mode is fully compatible with the AVR SPI regarding:
However, since the USART in MSPIM mode reuses the USART resources, the use of the
USART in MSPIM mode is somewhat different compared to the SPI. In addition to differences of
the control register bits, and that only master operation is supported by the USART in MSPIM
mode, the following features differ between the two modules:
A comparison of the USART in MSPIM mode and the SPI pins is shown in
Table 6-86.
• Master mode timing diagram.
• The UCPOLn bit functionality is identical to the SPI CPOL bit.
• The UCPHAn bit functionality is identical to the SPI CPHA bit.
• The UDORDn bit functionality is identical to the SPI DORD bit.
• The USART in MSPIM mode includes (double) buffering of the transmitter. The SPI has no
• The USART in MSPIM mode receiver includes an additional buffer level.
• The SPI WCOL (Write Collision) bit is not included in USART in MSPIM mode.
• The SPI double speed mode (SPI2X) bit is not included. However, the same effect is
• Interrupt timing is not compatible.
• Pin control differs due to the master only operation of the USART in MSPIM mode.
buffer.
achieved by setting UBRRn accordingly.
USART_MSPIM
XCKn
RxDn
TxDn
(N/A)
Comparison of USART in MSPIM Mode and SPI Pins.
MOSI
MISO
SCK
SPI
SS
Comment
Master Out only
Master In only
(Functionally identical)
Not supported by USART in MSPIM
ATA6612/ATA6613
Table
6-86.
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