33.3. Block Diagram
Figure 33-1. Full-Duplex SPI Master Slave Interconnection
BAUD
baud rate generator
Tx DATA
shift register
rx buffer
Rx DATA
Master
Slave
Tx DATA
shift register
rx buffer
Rx DATA
SCK
_SS
MISO
MOSI
ADDR/ADDRMASK
==
Address Match
33.4. Signal Description
Table 33-1. SERCOM SPI Signals
Signal Name
Type
Description
PAD[3:0]
Digital I/O
General SERCOM pins
One signal can be mapped to one of several pins.
Related Links
I/O Multiplexing and Considerations
on page 27
33.5. Product Dependencies
In order to use this peripheral, other parts of the system must be configured correctly, as described below.
33.5.1. I/O Lines
In order to use the SERCOM’s I/O lines, the I/O pins must be configured using the IO Pin Controller
(PORT).
When the SERCOM is configured for SPI operation, the SERCOM controls the direction and value of the
I/O pins according to the table below. Both PORT control bits PINCFGn.PULLEN and PINCFGn.DRVSTR
are still effective. If the receiver is disabled, the data input pin can be used for other purposes. In master
mode, the slave select line (SS) is hardware controlled when the Master Slave Select Enable bit in the
Control B register (CTRLB.MSSEN) is '1'.
Table 33-2. SPI Pin Configuration
Pin
Master SPI
Slave SPI
MOSI
Output
Input
MISO
Input
Output
SCK
Output
Input
SS
Output (CTRLB.MSSEN=1)
Input
The combined configuration of PORT, the Data In Pinout and the Data Out Pinout bit groups in the
Control A register (CTRLA.DIPO and CTRLA.DOPO) define the physical position of the SPI signals in the
table above.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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